Liquid container having a liquid consumption detecting device therein

ABSTRACT

An ink cartridge serving as a liquid container, comprises a liquid sensor having a piezoelectric element which detects a consumption state of the liquid contained in the container, and a consumption data memory as a memory means. The consumption data memory is a rewritable memory which stores consumption related data which are related to the detection of the consumption state using the liquid sensor. The consumption related data are, for example, consumption state data as a result of the detection. Even when the ink cartridge is removed, the consumption state data can still be utilized. The consumption related data may be a detection characteristic detected depending on the consumption state of the liquid. Based on this detection characteristic, the consumption state is detected utilizing the liquid sensor. The consumption state can be detected irrespective of individual differences of the ink cartridges.

[0001] This patent application claims priority based on a Japanesepatent applications, H. 11-139683 filed on May 20, 1999, H. 11-147538filed on May 27, 1999 and H. 11-256522 filed on Sep. 10, 1999, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a liquid container and a liquidconsumption. More particularly, the present invention relates to an inkcartridge to which a piezoelectric device detecting an ink consumptionstate inside an ink cartridge supplying the liquid to a printing head ismounted and to which a memory means that stores ink consumption datadetected by the piezoelectric device is mounted.

[0004] 2. Description of the Related Art

[0005] In an ink-jet recording apparatus, a carriage thereof iscomprised of a pressure generating means which pressurizes a pressuregenerating chamber and a nozzle opening which discharges the pressurizedink therefrom as ink droplets. The ink-jet recording apparatus isstructured such that ink from the ink tank is being supplied to arecording head via a passage, so as to continuously perform a printingoperation. The ink tank is structured as a cartridge in a detachablemanner so that a user can replace it when ink is consumed out.

[0006] Conventionally, as a method of controlling the ink consumption ofthe ink cartridge, a method is known of controlling the ink consumptionby means of a calculation in which the counted number of ink dropletsdischarged by the recording head and the amount of ink sucked in amaintenance process of the printing head are integrated by software, andanother method of controlling the ink consumption in which the time atwhich the ink is actually consumed is detected by directly mounting tothe ink cartridge the electrodes for use in detecting the liquidsurface, and so forth.

[0007] Moreover, in the calculation-based method of controlling the inkconsumption by integrating the discharged number of ink droplets and theamount of ink or the like by the software, there is a problem where theink consumption amount inside the ink cartridge can not be detected. Asfor the method of controlling by electrodes the time at which the ink isconsumed, there remain problems such as limitation to the types of inkand the complicated sealing structure of the electrodes and so on thougha structure for detecting the ink consumption may be somehow proposed.

[0008] However, in the calculation-based method of controlling the inkconsumption by integrating the discharged number of ink droplets and theamount of ink or the like by the software, there are problems where anerror occurs due to a printing mode and so on at a user's side andanother unwanted error occurs when the same cartridge is mounted again.Moreover, the pressure inside the ink cartridge and the viscosity of theink change depending on usage environment such as ambient temperatureand humidity, elapsed time after an ink cartridge has been opened foruse, and usage frequency at a user side. Thus, a problem is caused wherea considerable error occurs between the calculated ink consumption andthe actual ink consumption.

[0009] On the other hand, in the method of controlling by electrodes thetime at which the ink is consumed, as disclosed for example in theJapanese Patent Application Laid-Open No. Hei8-34123, whether or not theink is present can be controlled with high reliability since the liquidsurface of ink can be actually detected. actual ink consumption can bedetected at one point. However, since detecting the liquid surface ofink relies on the ink conductivity, there are problems in that types ofink which can be detected might be limited and a sealing structure ofthe electrodes becomes complicated. Moreover, since precious metal isusually used as the electrode material, which is highly conductive anderosive, manufacturing costs of the ink cartridge increases thereby.Moreover, since it is necessary to attach the two electrodes to twoseparate positions of the ink cartridge, the manufacturing processincreases, thus causing a problem which increases the manufacturingcosts.

[0010] Moreover, when the ink cartridge scans together with therecording head of the ink-jet recording apparatus, there are occasionswhere undulated waves are caused and bubbles generated. The bubbles maycause erroneous operation in the course of detecting whether or not theink is present. In particular, in apparatus which directly detects theink consumption amount using the electrodes to control the point atwhich the ink is consumed, the erroneous operation due to bubbles aresignificant.

[0011] There is an occasion where a cavity is provided in an inkdetecting portion inside the cartridge, in apparatus which directlydetects the ink consumption amount using the electrodes to control thepoint at which the ink is consumed. That there exists ink in the cavitymay cause erroneous detection.

SUMMARY OF THE INVENTION

[0012] Therefore, the present invention has been made in view of theforegoing drawbacks and it is an object of the present invention toprovide a liquid container capable of reliably detecting a liquidconsumption status and dispensing with a complicated sealing structure.It is another object of the present invention to provide an inkcartridge capable of reliably detecting the ink consumption amount andcapable of dispensing with a complicated sealing structure. Theseobjects are achieved by combinations described in the independentclaims. The dependent claims define further advantageous and exemplarycombinations of the present invention.

[0013] The present invention provides a technology of detecting theliquid remaining amount by utilizing vibration in particular, and such atechnology is improved. The present invention makes possible suitableutilization of detection result, and improves detection accuracy.Moreover, the present invention is not limited to the ink cartridge andcan be applied to detecting the other liquid contained in the liquidcontainer.

[0014] The above object can be achieved by providing a liquid containermounted to a liquid utilizing apparatus, which comprises a liquid sensorhaving a piezoelectric element and a memory means which stores datarelated to liquid consumption status detected by the liquid sensor. Inparticular, the above object can be achieved by providing an inkcartridge mounted to an ink-jet recording apparatus, which comprises aliquid sensor having a piezoelectric element and a memory means whichstores data related to liquid consumption status detected by the liquidsensor.

[0015] According to the present invention, the liquid utilizingapparatus is typically an ink-jet recording apparatus while the liquidcontainer is typically an ink cartridge. The liquid container accordingto the present invention comprises a liquid sensor having apiezoelectric element and a memory means. Preferably, a detection signalis generated which indicates vibration of the piezoelectric elementcorresponding to the liquid consumption state inside the container. Thememory means stores data related to the liquid container. The memorymeans is preferably a consumption data memory, and the consumption datamemory is rewritable, and stores the consumption related data whichrelate to detecting the consumption state using the liquid sensor. Byutilizing the piezoelectric element, the consumption state can beappropriately detected without leakage. By providing the memory meanswhich is associated with the piezoelectric element, each liquidcontainer can have the consumption related data necessary for the liquidcontainer.

[0016] The consumption related data may be consumption state dataobtained by using the liquid sensor. For example, suppose that theliquid container is removed from the liquid utilizing apparatus with theliquid having been halfway consumed. When the liquid container ismounted again or mounted to another apparatus, the consumption state isread out of the memory means so as to be used. The detection result canbe prevented from being lost accompanied by removal of the container. Auser is informed of the consumption state, and a control based on theconsumption state is possible. In this manner, according to the presentinvention, suitable utilization of the detection result is possible. Inaddition to the consumption state detected by the liquid sensor, thememory means may store the consumption state estimated from the printingamount.

[0017] The consumption related data may be detection characteristic datautilized in the course of obtaining the consumption status using theliquid sensor, and are preferably data detected corresponding to theconsumption state. The consumption state is detected based on thedetection characteristic data using the liquid sensor. The detectioncharacteristic data may be data indicating acoustic impedance and arepreferably data on a resonant frequency. For example, suppose that acontrol computer of the ink-jet recording apparatus has a detectionprocessing capability. This control computer may obtain the detectioncharacteristic data from the cartridge at the time when the inkcartridge is mounted.

[0018] The present invention is advantageous if there are differencesamong the liquid containers having unique detection characteristics. Dueto irregularity in the shape of the container and other various factors,the detection characteristic of the sensor provided in the liquidcontainer differs per a container. Thus, preferably, the detectioncharacteristic intrinsic to each container is measured and stored in thememory means. Utilizing this detection characteristic, the effect causedby the irregularity among containers can be reduced so as to improve thedetection accuracy.

[0019] The detection characteristic data may be detection characteristicdata prior to the consumption which indicate the detectioncharacteristic (acoustic impedance and so on) before the liquid insidethe liquid container is consumed. Moreover, the detection characteristicdata may be the detection characteristic data after the consumptionwhich indicate the detection characteristic expected when the liquid hasbeen consumed up to a predetermined detection target. Of course, boththe detection characteristic data prior to the consumption and thedetection characteristic data after the consumption maybe stored.

[0020] The memory means (consumption data memory) may store the measuredvalues in the detection characteristic data after the liquid containeris mounted to apparatus utilizing the liquid of the liquid container.For example, immediately after the ink cartridge is mounted to theink-jet recording apparatus, the acoustic impedance is detected by usingthe liquid sensor. That measured value is stored in the consumption datamemory, and is utilized as the detection characteristic data after thestart of ink usage. The detection characteristic which is prepared inadvance may be corrected by the measured value. By these adjustments atinitial stages, the irregularity due to the individual differences ofthe containers can be suitably alleviated so as to improve the detectionaccuracy

[0021] The memory means (consumption data memory) may store the measuredvalue in the detection characteristic data, in a manufacturing processof the liquid container. Since the measured value is obtained in themanufacturing process, a measured value of the detection characteristicprior to the liquid injection can also be obtained. Both or either ofthe detection characteristic data prior to the consumption and thedetection characteristic data after the consumption may be easilystored.

[0022] The memory means may store the data prior to the consumption. Thememory means may store data on change in consumed amount.

[0023] The memory means may store data on the ink. The memory means maystore data on the type of ink. The data on the type of ink may be dataobtained by the liquid sensor.

[0024] The liquid sensor and the memory means may be arranged indifferent positions on the liquid container. The liquid sensor and thememory means may be arranged in different positions on the same wallsurface of the liquid container. The liquid sensor and the memory meansmay be arranged on different wall surfaces of the liquid container. Thewall surface on which the liquid sensor is arranged may be perpendicularto the wall surface on which the memory means (consumption data memory)is arranged.

[0025] The liquid sensor and the memory means may be provided in thecenter in the cross direction of the container. The liquid sensor andthe memory means may be provided in the vicinity of a supply port whichsupplies the liquid from the liquid container, and be provided in thecenter in the cross direction of the container. An advantageous aspectis obtained where a position displacement of the liquid sensor and thememory against the container being aslope at the time of mounting can bereduced. Moreover, utilizing the positioning structure of the supplyport, the position displacement of the liquid sensor and the memory canbe reduced.

[0026] The liquid sensor and the memory means may be provided on thesame base plate (consumption detection base plate). The liquid sensorand the memory means are easily mounted. The base plate is in thevicinity of the supply port which supplies the liquid from the liquidcontainer, and may be arranged in the center in the cross direction ofthe container, so that the position displacement can be reduced asdescribed above.

[0027] Moreover, a mounting module in which the liquid sensor and themounting structure are integrally formed may be attached to the baseplate. The liquid sensor can be protected from externally. Moreover,mounting can be performed with ease so as to result in cost reduction.

[0028] There may be provided a positioning structure whichpositioning-performs on the base plate to the liquid container. Themounting position accuracy can be improved.

[0029] Preferably, the consumption state is detected based on the changein the acoustic impedance accompanied by the liquid consumption. Theliquid sensor may output a signal which indicates a residual vibratingstate after the vibration is generated. The liquid consumption isdetected based on the fact that the residual vibrating state changescorresponding to the liquid consumption state.

[0030] Moreover, the liquid sensor may generate an elastic wave towardthe interior of the liquid container, and may generate a detectionsignal corresponding to a reflected wave of the elastic wave.

[0031] The memory means may be a semiconductor memory such as an EEPROM.

[0032] Another mode of the present invention is a liquid detectingdevice. The liquid detecting device comprises a liquid sensor and amemory means. The liquid sensor includes a piezoelectric element. Adetection signal is generated which indicates vibration of thepiezoelectric element corresponding to the liquid consumption stateinside the liquid container. The memory means is rewritable and storesthe consumption related data which relate to detecting the consumptionstate using the liquid sensor.

[0033] In this embodiment, both or either of the liquid sensor and thememory need not be provided in the liquid sensor. A detection processingmechanism using the liquid sensor may be provided in the liquidutilizing apparatus on in an external apparatus connected thereto, orarranged in the liquid container or provided at a plurality oflocations.

[0034] For example, suppose that the liquid sensor is provided in theliquid container, and the memory and the detection processing mechanismare mounted in the liquid utilizing apparatus. The detection processingmechanism identifies the liquid container and reads out the consumptionrelated data corresponding to that liquid from the memory means so as tobe used.

[0035] In still another embodiment according to the present invention,there is provided a liquid consumption detecting base plate which isused for detecting the consumption state of the liquid inside the liquidcontainer, which includes a sensor and a memory means.

[0036] This summary of the invention does not necessarily describe allnecessary features of the present invention. The present invention mayalso be a sub-combination of the above described features. The above andother features and advantages of the present invention will become moreapparent from the following description of embodiments taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037]FIG. 1 shows an embodiment of an ink cartridge for use with asingle color, for example, the black ink.

[0038]FIG. 2 shows an embodiment of the ink cartridge which houses aplural types of inks.

[0039]FIG. 3. shows an ink-jet recording apparatus suitable for the inkcartridges shown in FIG. 1 and FIG. 2, according to an embodiment of thepresent invention.

[0040]FIG. 4 is a detailed cross sectional view of a sub-tank unit 33.

[0041] FIGS. 5(I)-5(V) show manufacturing methods o elastic wavegenerating means 3, 15, 16 and 17.

[0042]FIG. 6 shows another embodiment of the elastic wave generatingmeans 3 shown in FIG. 5.

[0043]FIG. 7 shows an ink cartridge according to another embodiment ofthe present invention.

[0044]FIG. 8 shows an ink cartridge according to still anotherembodiment of the present invention.

[0045]FIG. 9 shows an ink cartridge according to still anotherembodiment of the present invention.

[0046]FIG. 10 shows an ink cartridge according to still anotherembodiment of the present invention.

[0047]FIG. 11 shows an ink cartridge according to still anotherembodiment of the present invention.

[0048]FIG. 12A and FIG. 12B shows another embodiments of the inkcartridge shown in FIG. 11.

[0049]FIG. 13A and FIG. 13B show ink cartridges according to stillanother embodiment of the present invention.

[0050]FIGS. 14A, 14B and 14C show plan views of the through hole 1 caccording to another embodiment.

[0051]FIGS. 15A and 15B show cross sections of the ink-jet recordingapparatus according to still another embodiment of the presentinvention.

[0052]FIGS. 16A and 16B show an embodiment of the ink cartridge suitablefor the recording apparatus shown in FIGS. 15A and 15B.

[0053]FIG. 17 shows an ink cartridge 272 according to still anotherembodiment of the present invention.

[0054]FIG. 18 shows an ink cartridge 272 and an ink-jet recordingapparatus according to still another embodiment of the presentinvention.

[0055]FIG. 19 shows still another embodiment of the ink cartridge 272shown in FIG. 16.

[0056]FIGS. 20A, 20B and 20C show details of the actuator 106.

[0057]FIGS. 21A, 21B, 21C, 21D, 21E and 21F show periphery andequivalent circuits of the actuator 106.

[0058]FIGS. 22A and 22B show relationship between the ink density andink resonant frequency detected by the actuator 106.

[0059]FIGS. 23A and 23B show waveforms of the counter electromotiveforce of the actuator 106.

[0060]FIG. 24 shows another embodiment of the actuator 106.

[0061]FIG. 25 shows a cross section of a part of the actuator 106 shownin FIG. 24.

[0062]FIG. 26 shows a cross section of the entire actuator 106 shown inFIG. 24.

[0063]FIG. 27 shows a manufacturing method of the actuator 106 shown inFIG. 24.

[0064]FIGS. 28A, 28B and 28C show an ink cartridge according to stillanother embodiment of the present invention.

[0065]FIGS. 29A, 29B and 29C show another embodiment of the through hole1 c.

[0066]FIG. 30 shows an actuator 660 according to another embodiment.

[0067]FIGS. 31A and 31B show an actuator 670 according to still anotherembodiment.

[0068]FIG. 32 is a perspective view showing a module 100.

[0069]FIG. 33 is an exploded view showing the structure of the module100 shown in FIG. 32.

[0070]FIG. 34 shows another embodiment of the module 100.

[0071]FIG. 35 is an exploded view showing the structure of the module100 shown in FIG. 34.

[0072]FIG. 36 shows still another embodiment of the module 100.

[0073]FIG. 37 shows an exemplary cross section of the module 100 shownin FIG. 32 where the module 100 is mounted to the ink container.

[0074]FIGS. 38A, 38B and 38C show still another embodiment of the module100.

[0075]FIG. 39 shows an embodiment of the an ink cartridge using theactuator 106 shown in FIG. 20 and FIG. 21 and an ink-jet recordingapparatus therefor.

[0076]FIG. 40 shows a detail of the ink-jet recoding apparatus.

[0077]FIGS. 41A and 41B show another embodiments of the ink cartridge180 shown in FIG. 40.

[0078]FIGS. 42A, 42B and 42C show still another embodiment of the inkcartridge 180.

[0079]FIGS. 43A, 43B and 43C show still another embodiment of the inkcartridge 180.

[0080]FIGS. 44A, 44B, 44C and 44D show still another embodiment of theink cartridge 180.

[0081]FIGS. 45A, 45B and 45C show another embodiments of the ink a,cartridge 180 shown in FIG. 44C.

[0082]FIGS. 46A, 46B, 46C and 46D show still another embodiment of theink cartridge using the module 100.

[0083]FIG. 47 is a block diagram showing structure of the ink cartridgeto which the liquid sensor and the consumption data memory are provided

[0084]FIG. 48 shows a processing of the consumption detecting processunit 812 utilizing the consumption data memory 804.

[0085]FIG. 49 shows a recording timing of the detection characteristicto the consumption data memory.

[0086]FIG. 50 is an exemplary configuration showing an arrangement ofthe liquid sensor and the consumption data memory in the ink cartridge.

[0087]FIGS. 51A and 51B show an exemplary positioning of the supplyport.

[0088]FIG. 52 is an exemplary configuration showing an arrangement ofthe supply port in the ink cartridge.

[0089]FIG. 53 is a functional block diagram for an ink-jet recordingapparatus equipped with the ink consumption detecting device accordingto the present embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0090] The invention will now be described based on the preferredembodiments, which do not intend to limit the scope of the presentinvention, but exemplify the invention. All of the features and thecombinations thereof described in the embodiment are not necessarilyessential to the invention.

[0091] First of all, the principle of the present embodiment will bedescribed. In the present embodiment, the present invention is appliedto a technology by which to detect ink consumption state inside an inkcontainer. The ink consumption state is detected by utilizing a liquidsensor including a piezoelectric element. The liquid sensor generates adetection signal which indicates vibration of the piezoelectric elementcorresponding to the ink consumption state.

[0092] As a feature of the present embodiment, in addition to the liquidsensor, a consumption data memory is provided in an ink cartridge. Theconsumption data memory is one which embodies the memory means for usewith the liquid container in the present invention. The consumption datamemory is rewritable and stores the consumption related data whichrelate to consumption state using the liquid sensor. By providing theconsumption data memory, each liquid container can have the consumptionrelated data necessary for each liquid container.

[0093] For example, the consumption related data are consumption statedata obtained by using the liquid sensor. Suppose that an ink cartridgeis removed from the ink-jet recording apparatus, and is mounted again.Since the consumption state data are held in the memory, loss of theconsumption state data can be prevented. At the time of mounting, theconsumption state data can be utilized by reading them out of thememory.

[0094] Moreover, the consumption related data may be data on detectioncharacteristics detected corresponding to the consumption of the liquid.The detection related data are, for example, data indicating an acousticimpedance corresponding to the ink consumption state. This detectioncharacteristic data are read out and utilized in detecting theconsumption state. According to this embodiment, the ink-jet device neednot have the detection characteristic data. A possible change indetection characteristics due to a design change of the cartridge may becoped with suitably.

[0095] The present embodiment is advantageous in case the ink cartridgeshave individual differences among them. The detection characteristicdiffers slightly among cartridges due to a manufacturing irregularityand so on. By storing the detection characteristics of individualcartridges in the consumption data memory, the effect caused by theindividual difference can be reduced so as to improve the detectionaccuracy.

[0096] Moreover, the consumption data memory, as a memory means in thepresent invention, stores the ink related data therein. The memory meansalso stores data on a type of ink and so on. Moreover, this memory meansstores other data such as a manufacturing data, cleaning sequence data,image processing data and so on.

[0097] Hereinbelow, the present embodiments will be further described indetail with reference of drawings. First, fundamental of the technologywhich detects the ink consumption based on vibration utilizing apiezoelectric device will be described, which is followed by variousapplications of the detection technology. In the present embodiment, theink cartridge includes a liquid sensor and a consumption data memory.Thereafter, what is related to the consumption data memory will bedescribed in detail.

[0098] In the present embodiment, the liquid sensor is constitutedspecifically by a piezoelectric device. In the following description, anactuator and an elastic wave generating means correspond to the liquidsensor. The consumption data memory is a semiconductor memory(semiconductor memory means). Cartridge which detects the inkconsumption

[0099]FIG. 1 is a cross sectional view of an embodiment of an inkcartridge for use with a single color, for example, the black ink. Inthe ink cartridge shown in FIG. 1, the detection method implemented isbased on a method, among methods described above, in which the positionof the liquid surface in the liquid container and whether or not theliquid is empty are detected by receiving the reflected wave of theelastic wave. As a means for generating and receiving the elastic wave,an elastic wave generating means 3 is utilized. An ink supply port 2which comes in contact with an ink supply needle of the recordingapparatus in a sealed manner is provided in a container 1 which housesthe ink. In an outside portion of a bottom face 1 a of the container 1,the elastic wave generating means 3 is mounted such that the elasticwave can be communicated, via the container, to the ink inside thecontainer. In order that at a stage at which the ink K is almost usedup, i.e. at the time when the ink becomes an ink-end state, the transferof the elastic wave can change from the liquid to the gas, the elasticwave generating means 3 is provided in a slightly upward position fromthe ink supply port 2. Moreover, an elastic wave receiving means may beseparately provided instead, so that the elastic wave generating means 3is used as an elastic wave generating means only.

[0100] A packing ring 4 and a valve body 6 are provided in the inksupply port 2. Referring to FIG. 3, the packing ring 4 is engaged withthe ink supply needle 32 communicating with a recording head 31, in afluid-tight manner. The valve body 6 is constantly and elasticallycontacted against the packing ring 4 by way of a spring 5. When the inksupply needle 32 is inserted, the valve body 6 is pressed by the inksupply needle 32 so as to open an ink passage, so that ink inside thecontainer 1 is supplied to the recording head 31 via the ink supply port2 and the ink supply needle 32. On an upper wall of the container 1,there is mounted a semiconductor memory means 7 which stores data on inkinside the ink cartridge.

[0101]FIG. 2 is a perspective view of the ink cartridge which storesplural types of inks, viewed from a back side thereof, according to anembodiment. A container 8 is divided by division walls into three inkchambers 9, 10 and 11. Ink supply ports 12, 13 and 14 are formed for therespective ink chambers. In a bottom face 8 a of the respective inkchambers 9, 10 and 11, the respective elastic wave generating means 15,16 and 17 are mounted so that the elastic waves can be transferred tothe ink housed in each ink chamber via the container.

[0102]FIG. 3 is a cross sectional view showing an embodiment of a majorpart of the ink-jet recording apparatus suitable for the ink cartridgeshown in FIG. 1 and FIG. 2. A carriage 30 capable of reciprocating inthe direction of the width of the recording paper is equipped with asub-tank unit 33, while the recording head 31 is provided in a lowerface of the sub-tank unit 33. Moreover, the ink supply needle 32 isprovided in an ink cartridge mounting face side of the sub-tank unit 33.

[0103]FIG. 4 is a detailed cross sectional view of a sub-tank unit 33.The sub-tank unit 33 comprises the ink supply needle 32, the ink chamber34, a flexible valve 36 and a filter 37. In the ink chamber 34, the inkis housed which is supplied from the ink cartridge via ink supply needle32. The flexible valve 36 is so designed that the flexible valve 36 isopened and closed by means of the pressure difference between the inkchamber 34 and the ink supply passage 35. The sub-tank unit 33 is soconstructed that the ink supply passage 35 is communicated with therecording head 31 so that the ink can be supplied up to the recordinghead 31.

[0104] Referring to FIG. 3, when the ink supply port 2 of the container1 is inserted through the ink supply needle 32 of the sub-tank unit 33,the valve body 6 recedes against the spring 5, so that an ink passage isformed and the ink inside the container 1 flows into the ink chamber 34.At a stage where the ink chamber 34 is filled with ink, a negativepressure is applied to a nozzle opening of the recording head 31 so asto fill the recording head with ink. Thereafter, the recording operationis performed.

[0105] When the ink is consumed in the recording head 31 by therecording operation, a pressure in the downstream of the flexible valve36 decreases. Then, the flexible valve 36 is positioned away from avalve body 38 so as to become opened. When the flexible valve 36 isopened, the ink in the ink chamber 34 flows into the recording head 31through the ink passage 35. Accompanied by the ink which has flowed intothe recording head 31, the ink in the container 1 flows into thesub-tank unit 33 via the ink supply needle 32.

[0106] While the recording apparatus is operating, a drive signal issupplied to the elastic wave generating means 3 at a detection timingwhich is set in advance, for example, at a certain period of time. Theelastic wave generated by the elastic wave generating means 3 istransferred to the ink by propagating through the bottom face 1 a of thecontainer 1 so as to be propagated to the ink.

[0107] By adhering the elastic wave generating means 3 to the container1, the ink cartridge itself is given an ink remaining amount detectingcapability. According to the present embodiment, since a process ofembedding electrodes for use in detecting the liquid surface isunnecessary in the course of forming the container 1, an injectionmolding process can be simplified and the leakage of the liquid from aplace in which the electrodes are supposedly embedded can be avoided,thus improving the reliability of the ink cartridge.

[0108] FIGS. 5(I)-5(V) show manufacturing methods of the elastic wavegenerating means 3, 15, 16 and 17. A base plate 20 is formed by materialsuch as the burning-endurable ceramic. Referring to FIG. 5(I), first ofall, a conductive material layer 21 which becomes an electrode at oneside is formed on the base plate 20. Next, referring to FIG. 5(II), agreen sheet 22 serving as piezoelectric material is placed on theconductive material layer 21. Next, referring to FIG. 5(III), the greensheet 22 is formed in a predetermined shape by a press processing or thelike and is made into the form of a vibrator, and is air-dried.Thereafter, the burning is performed on the green sheet 22 at a burningtemperature of, for example, 1200° C. Next, referring to FIG. 5(IV), aconductive material layer 23 serving as other electrode is formed on thesurface of the green sheet 22 so as to be polarized in aflexural-oscillatable manner. Finally, referring to FIG. 5(V), the baseplate 20 is cut along each element. By fixing the base plate 20 in apredetermined face of the container 1 by use of adhesive or the like,the elastic wave generating means 3 can be fixed on the predeterminedface of the container and the ink cartridge is completed which has abuilt-in function which detects the ink remaining amount.

[0109]FIG. 6 shows another embodiment of the elastic wave generatingmeans 3 shown in FIG. 5. In the embodiment shown in FIG. 5, theconductive material layer 21 is used as a connecting electrode. On theother hand, in the embodiment shown in FIG. 6, connecting terminals 21 aand 23 a are formed by a solder in an upper position than the surface ofthe piezoelectric material layer comprised of the green sheet 22. By theprovision of the connecting terminals 21 a and 23 a, the elastic wavegenerating means 3 can be directly mounted to the circuit board, so thatinefficient connection such as one by lead wires can be avoided.

[0110] Now, the elastic wave is a type of waves which can propagatethrough gas, liquid and solid as medium. Thus, the wavelength,amplitude, phase, frequency, propagating direction and propagatingvelocity of the elastic wave change based on the change of medium inquestion. On the other hand, the state and characteristic of thereflected wave of the elastic wave change according to the change of themedium. Thus, by utilizing the reflected wave which changes based on thechange of the medium through which the elastic wave propagates, thestate of the medium can be observed. In a case where the state of theliquid inside the liquid container is to be detected by this method, anelastic wave transmitter-receiver will be used for example. Let usexplain this by referring to embodiments shown in FIGS. 1-3. First, thetransmitter-receiver gives out the elastic wave to the medium, forexample, the liquid or the liquid container. Then, the elastic wavepropagates through the medium and arrives at the surface of the liquid.Since a boundary is formed between the liquid and the gas on the liquidsurface, the reflected wave is returned to the transmitter-receiver. Thetransmitter-receiver receives the reflected wave. A distance between theliquid surface and a transmitter or receiver can be measured based on anoverall traveled time of the reflected wave, or a damping factor of theamplitudes of the elastic wave generated by the transmitter and thereflected wave reflected on the liquid surface, and so on. Utilizingthese, the state of the liquid inside the liquid container can bedetected. The elastic wave generating means 3 may be used as a singleunit of the transmitter-receiver in the method utilizing the reflectedwave based on the change of the medium through which the elastic wavepropagates, or a separately provided receiver may be mounted thereto.

[0111] As described above, in the elastic wave, generated by the elasticwave generating means 3, propagating through the ink liquid, thetraveling time of the reflected wave occurring on the ink liquid surfaceto arrive at the elastic wave generating means 3 varies depending ondensity of the ink liquid and the liquid level. Thus, if the compositionof ink is fixed, the traveling time of the reflected wave which occurredin the ink liquid surface varies depending on the ink amount. Therefore,the ink amount can be detected by detecting the time period during whichthe elastic wave generating means 3 generates the elastic wave and thenthe wave reflected from the ink surface arrives at the elastic wavegenerating means 3. Moreover, the elastic wave vibrates particlescontained in the ink. Thus, in a case of using pigment-like ink whichuses pigment as a coloring agent, the elastic wave contributes toprevent precipitation of the pigment or the like.

[0112] By providing the elastic wave generating means 3 in the container1, when the ink of the ink cartridge approaches (decreases to) anink-end state and the elastic wave generating means 3 can no longerreceive the reflected wave, it is judged as an ink-near-end and thus cangive indication to replace the cartridge.

[0113]FIG. 7 shows an ink cartridge according to another embodiment ofthe present invention. Plural elastic wave generating means 41-44 areprovided on the side wall of the container 1, spaced at a variableinterval from one another in the vertical direction. In the inkcartridge shown in FIG. 7, whether or not the ink is present at mountinglevels of respective elastic wave generating means 41-44 can be detectedby whether or not the ink is present at respective positions of theelastic wave generating means 41-44. For example, suppose that theliquid level of ink is at a point between the elastic wave generatingmeans 44 and 43. Then, the elastic wave generating means 44 detects andjudges that the ink is empty while the elastic wave generating means 41,42 and 43 detect and judge respectively that the ink is present. Thus,it can be known that the liquid level of ink lies in a level between theelastic wave generating means 44 and 43. Thus, provision of the pluralelastic wave generating means 41-44 makes possible to detect the inkremaining amount in a step-by-step manner.

[0114]FIG. 8 and FIG. 9 show ink cartridges according to still anotherembodiments of the present invention. In an embodiment shown in FIG. 8,an elastic wave generating means 65 is mounted in a bottom face 1 aformed aslope in the vertical direction. In an embodiment shown in FIG.9, an elastic wave generating means 66 of an elongated shape in thevertical direction is provided in the vicinity of the bottom face of aside wall 1 b.

[0115] According to the embodiments shown in FIG. 8 and FIG. 9, whenpart of the elastic wave generating means 65 and 66 is exposed from theliquid surface, the traveled time of the reflected wave and the acousticimpedance of the elastic waves generated by the elastic wave generatingmeans 65 continuously change corresponding to the change (Δh1, Δh2) ofthe liquid surface. Thus, the process from the ink-near-end state to theink-end state of ink remaining amount can be accurately detected bydetecting the degree of change in the traveled time of the reflectedwave or the acoustic impedance of the elastic waves.

[0116] In the above embodiments, description has been made byexemplifying the ink cartridge of a type where the ink is directlystored in the liquid container. As still another embodiment of the inkcartridge, the above-described elastic wave generating means may bemounted on an ink cartridge of another type where the container 1 isloaded with a porous elastic member and the porous elastic member isimpregnated with the liquid ink. Though in the above embodiments aflexural oscillating type piezoelectric vibrator is used so as tosuppress the increase of the cartridge size, a vertically vibrating typepiezoelectric vibrator may also be used. In the above embodiments, theelastic wave is transmitted and received by a same elastic wavegenerating means. In still another embodiment, the elastic wavegenerating means may be provided separately as one for use intransmitting the elastic wave and other for receiving the elastic wave,so as to detect the ink remaining amount.

[0117]FIG. 10 shows an ink cartridge according to still anotherembodiment of the present invention. Plural elastic wave generatingmeans 65 a, 65 b and 65 c on the bottom face 1 a formed aslope in thevertical direction spaced at an interval are provided in the container1. According to the present embodiment, the arrival time (traveled time)of the reflected waves of the elastic waves to the respective elasticwave generating means 65 a, 65 b and 65 c in the respective mountingpositions of the elastic wave generating means 65 a, 65 b and 65 cdiffers depending on whether or not the ink is present in the respectivepositions of the plural elastic wave generating means 65 a, 65 b and 65c. Thus, whether or not the ink is present in the respective mountedposition levels of the elastic wave generating means 65 a, 65 b and 65 ccan be detected by scanning each elastic generating means (65 a, 65 band 65 c) and by detecting the traveled time of the reflected wave ofthe elastic wave in the elastic wave generating means 65 a, 65 b and 65c. Hence, the ink remaining amount can be detected in a step-by-stepmanner. For example, suppose that the liquid level of ink is at a pointbetween the elastic wave generating means 65 b and 65 c. Then, theelastic wave generating means 65 c detects and judges that the ink isempty while the elastic wave generating means 65 a and 65 b detect andjudge respectively that the ink is present. By overall evaluating theseresults, it becomes known that the liquid level of ink lies in a levelbetween the elastic wave generating means 65 b and 65 c.

[0118]FIG. 11 shows an ink cartridge according to still anotherembodiment of the present invention. In the ink cartridge shown in FIG.11, a floating board 67 attached to a floater 68 covers the ink liquidsurface in order to increase intensity of the reflected wave from theliquid surface. The floating board 67 is formed by material which has ahigh acoustic impedance therein and is ink-resistant, such as a ceramicboard.

[0119]FIG. 12A and FIG. 12B shows another embodiments of the inkcartridge shown in FIG. 11. In the ink cartridge shown in FIGS. 12A and12b, similar to one shown in FIG. 11, a floating board 67 attached to afloater 68 covers the ink liquid surface in order to increase intensityof the reflected wave from the liquid surface. Referring to FIG. 12A,the elastic wave generating means 65 is fixed on the bottom face 1 aformed aslope in the vertical direction. When the ink remaining amountbecomes scarce and thus the elastic wave generating means 65 is exposedfrom the liquid surface, the arrival time of the reflected wave of theelastic waves generated by the elastic wave generating means 65 at theelastic wave generating means 65 changes, thus whether or not the ink ispresent in the mounting position levels of the elastic wave generatingmeans 65 can be detected. Since the elastic wave generating means 65 ismounted in the bottom face 1 a formed aslope in the vertical direction,a small amount of ink still remains even after the elastic wavegenerating means 65 detects and judges that ink is empty. Thus, the inkremaining amount at an ink-near-end point can be detected.

[0120] Referring to FIG. 12B, plural elastic wave generating means 65 a,65 b and 65 c on the bottom face 1 a formed aslope in the verticaldirection spaced at an interval are provided in the container 1.According to the present embodiment shown in FIG. 12B, the arrival time(traveled time) of the reflected waves of the elastic waves at therespective elastic wave generating means 65 a, 65 b and 65 c in therespective mounting positions of the elastic wave generating means 65 a,65 b and 65 c differs depending on whether or not the ink is present inthe respective positions of the plural elastic wave generating means 65a, 65 b and 65 c. Thus, whether or not the ink is present in therespective mounted position levels of the elastic wave generating means65 a, 65 b and 65 c can be detected by scanning each elastic generatingmeans (65 a, 65 b and 65 c) and by detecting the traveled time of thereflected wave of the elastic wave in the elastic wave generating means65 a, 65 b and 65 c. For example, suppose that the liquid level of inkis at a point between the elastic wave generating means 65 b and 65 c.Then, the elastic wave generating means 65 c detects and judges that theink is empty while the elastic wave generating means 65 a and 65 bdetect and judge respectively that the ink is present. By overallevaluating these results, it becomes known that the liquid level of inklies in a level between the elastic wave generating means 65 b and 65 c.

[0121]FIG. 13A and FIG. 13B show ink cartridges according to stillanother embodiment of the present invention. In the ink cartridge shownin FIG. 13A, an ink absorbing member 74 is arranged in such a mannerthat at least part of the ink absorbing member 74 is disposed counter toa through hole 1 c provided inside the container 1. An elastic wavegenerating means 70 is fixed to the bottom face 1 a of the container 1such that the elastic wave generating means 70 is positioned counter tothe through hole 1 c. In the ink cartridge shown in FIG. 13B, an inkabsorbing member 75 is arranged in such a manner that the ink absorbingmember 75 is disposed counter to a groove 1 h formed so as tocommunicate with the through hole 1 c.

[0122] According to the present embodiment shown in FIGS. 13A and 13B,when the ink has been consumed and then the ink absorbing members 74 and75 are exposed from the ink, the ink in the ink absorbing members 74 and75 flows out by its dead weight, so that the ink is supplied to therecording head 31. When the ink is used up, the ink absorbing members 74and 75 absorb the ink remaining in the through hole 1 c, so that the inkis completely discharged from a concave part of the through hole 1 c.Thereby, the state of the reflected wave of the elastic wave generatedby the elastic wave generating means 70 changes at the time of theink-end state, thus the ink-end state can be further reliably detected.

[0123]FIGS. 14A, 14B and 14C show plan views of the through hole 1 caccording to another embodiment. As shown respectively in FIGS. 14A, 14Band 14C, the plane shape of the through hole 1 c may be of arbitraryshapes as long as the elastic wave generating means is capable of beingmounted thereto.

[0124]FIGS. 15A and 15B show cross sections of the ink-jet recordingapparatus according to still another embodiment of the presentinvention. FIG. 15A shows across section of the ink-jet recordingapparatus alone. FIG. 15B is a cross section of the ink-jet recordingapparatus to which the ink cartridge 272 is mounted. A carriage 250capable of reciprocating in the direction of the width of the ink-jetrecording paper includes a recording head 252 in a lower face thereof.The carriage 250 includes a sub-tank unit 256 in an upper face of therecording head 252. The sub-tank unit 256 has a similar structure tothat shown in FIG. 6. The sub-tank unit 256 has an ink supply needle 254facing an ink cartridge 272 mounting side. In the carriage 250, there isprovided a convex part 258 in a manner such that the convex part 258 isdisposed counter to a bottom portion of the ink cartridge 272 and in anarea where the ink cartridge 272 is to be mounted thereabove. The convexpart 258 includes an elastic wave generating means 260 such as thepiezoelectric vibrator.

[0125]FIGS. 16A and 16B show an embodiment of the ink cartridge suitablefor the recording apparatus shown in FIGS. 15A and 15B. FIG. 16A showsan embodiment of the ink cartridge for use with a single color, forinstance, the black color. The ink cartridge 272 according to thepresent embodiment, comprises a container which houses ink and an inksupply port 276 which comes in contact with an ink supply needle 254 ofthe recording apparatus in a sealed manner. In the container 274, thereis provided the concave part 278, positioned in a bottom face 274 a,which is to be engaged with the convex part 258. The c 280 concave part278 houses ultrasound transferring material such as gelated material.

[0126] The ink supply port 276 includes a packing ring 282, a valve body286 and a spring 284. The packing ring 282 is engaged with the inksupply needle 254 in a fluid-tight manner. The valve body 286 isconstantly and elastically contacted against the packing ring 282 by wayof the spring 284. When the ink supply needle 254 is inserted to the inksupply port 276, the valve body 286 is pressed by the ink supply needle254 so as to open an ink passage. On an upper wall of the container 274,there is mounted a semiconductor memory means 288 which stores data onink inside the ink cartridge and so on.

[0127]FIG. 16B shows an embodiment of the ink cartridge which housesplural types of ink. A container 290 is divided by division walls intoplural areas, that are, three ink chambers 292, 294 and 296. The inkchambers 292, 294 and 296 have ink supply ports 298, 300 and 302,respectively. In the area counter to respective ink chambers 292, 294and 296 in the bottom face 290 a of the container 290, the gelatedmaterial 304 and 306 to propagate the elastic waves generated by theelastic wave generating means 260 is housed in a cylindrical shapedconcave parts 310, 312 and 314.

[0128] Referring to FIG. 15B, when the ink supply port 276 of the inkcartridge 272 is inserted through the ink supply needle 254 of thesub-tank unit 256, the valve body 286 recedes against the spring 284, sothat an ink passage is formed and the ink inside the ink cartridge 272flows into the ink chamber 262. At a stage where the ink chamber 262 isfilled with ink, a negative pressure is applied to a nozzle opening ofthe recording head 252 so as to fill the recording head with ink.Thereafter, the recording operation is performed. When the ink isconsumed in the recording head 252 by the recording operation, apressure in the downstream of a flexible valve 266 decreases. Then, theflexible valve 266 is positioned away from a valve body 270 so as tobecome opened. When the flexible valve 36 is opened, the ink in the inkchamber 262 flows into the recording head 252 through the ink passage35. Accompanied by the ink which has flowed into the recording head 252,the ink in the ink cartridge 272 flows into the sub-tank unit 256.

[0129] While the recording apparatus is operating, a drive signal issupplied to the elastic wave generating means 260 at a detection timingwhich is set in advance, for example, at a certain period of time. Theelastic wave generated by the elastic wave generating means 260 isradiated from the convex part 258 and is transferred to the ink insidethe ink cartridge 272 by propagating through the gelated material 280 inthe bottom face 274 a of the ink cartridge 272. Though the elastic wavegenerating means 260 is provided in the carriage 250 in FIGS. 15A and15B, the elastic wave generating means 260 may be provided inside thesub-tank unit 256.

[0130] Since the elastic wave generated by the elastic wave generatingmeans 260 propagates through the ink liquid, the traveling time of thereflected wave occurring on the ink liquid surface to arrive at theelastic wave generating means 260 varies depending on density of the inkliquid and the liquid level. Thus, if the composition of ink is fixed,the traveling time of the reflected wave which occurred in the inkliquid surface varies depending on the ink amount. Therefore, the inkamount can be detected by detecting the time duration during which thereflected wave arrives at the elastic wave generating means 260 from theink liquid surface when the ink liquid surface is excited by the elasticwave generating means 260. Moreover, the elastic wave generated by theelastic wave generating mean 260 vibrates particles contained in theink. Thus, in a case of using pigment-like ink which uses pigment as acoloring agent, the elastic wave contributes to prevent precipitation ofthe pigment or the like.

[0131] After the printing operation and maintenance operation or thelike and when the ink of the ink cartridge approaches (decreases to) anink-end state and the elastic wave generating means 260 can no longerreceive the reflected wave even after the elastic wave generating meanssends out the elastic wave, it is judged that the ink is in anink-near-end state and thus this judgment can give indication to replacethe cartridge anew. Moreover, when the ink cartridge 272 is not mountedproperly to the carriage 250, the shape of the elastic wave from theelastic generating means 260 changes in an extreme manner. Utilizingthis, warning can be given to a user in the event that the extremechange in the elastic wave is detected, so as to prompt the user tocheck on the ink cartridge 272.

[0132] The traveling time of the reflected wave of the elastic wavegenerated by the elastic wave generating means 260 is affected by thedensity of ink housed in the container 274. Since the density of ink maydiffer by the type of ink used, data on the types of ink are stored in asemiconductor memory means 288, so that a detection sequence can be setbased on the data and thus the ink remaining amount can be furtherprecisely detected.

[0133]FIG. 17 shows an ink cartridge 272 according to still anotherembodiment of the present invention. In the ink cartridge 272 shown inFIG. 17, the bottom face 274 a is formed aslope in the verticaldirection.

[0134] In the ink cartridge 272 shown in FIG. 17, when the ink remainingamount is becoming low and part of a radiating area of the elastic wavegenerating means 260 is exposed from the liquid surface, the traveledtime of the reflected wave of the elastic waves generated by the elasticwave generating means 260 continuously changes corresponding to thechange Δh1 of the liquid surface. The Δh1 denotes change of the heightof the bottom face 274 a in both ends of the gelated material 280. Thus,the process from the ink-near-end state to the ink-end state of inkremaining amount can be accurately detected by detecting the degree ofchange in the traveled time of the reflected wave of the elastic wavegenerating means 260.

[0135]FIG. 18 shows an ink cartridge 272 and an ink-jet recordingapparatus according to still another embodiment of the presentinvention. The ink-jet recording apparatus shown in FIG. 18 includes aconvex part 258′ in a side face 274 b in an ink supply port 276 side ofthe ink cartridge 272. The convex part 258′ includes an elastic wavegenerating means 260′. Gelated material 280′ is provided in the sideface 274 b of the ink cartridge 272 so as to engage with the convex part258′. According to the ink cartridge 272 shown in FIG. 18, when the inkremaining amount is becoming low and part of a radiating area of theelastic wave generating means 260′ is exposed from the liquid surface,the acoustic impedance of the reflected wave of the elastic wavesgenerated by the elastic wave generating means 260′ continuously changecorresponding to the change Δh2 of the liquid surface. The Δh2 denotesdifference in the height of both ends of the gelated material 280′.Thus, the process from the ink-near-end state to the ink-end state ofink remaining amount can be accurately detected by detecting the degreeof change in the traveled time of the reflected wave of the elastic wavegenerating means 260 or change in the acoustic impedance.

[0136] In the above embodiments, description has been made byexemplifying the ink cartridge of a type where the ink is directlystored in the liquid container 274. As still another embodiment of theink cartridge, the above-described elastic wave generating means 260 maybe applied to an ink cartridge of another type where the container 274is loaded with a porous elastic member and the porous elastic member isimpregnated with the ink. In the above embodiments, the elastic wave istransmitted and received by the same elastic wave generating means 260and 260′ when the ink remaining amount is detected based on thereflected wave at the liquid surface. The present invention is notlimited thereby and for example, as still another embodiment the elasticwave generating means 260 may be provided separately as one for use intransmitting the elastic wave and other for receiving the elastic wave,so as to detect the ink remaining amount.

[0137]FIG. 19 shows still another embodiment of the ink cartridge 272shown in FIG. 16. A floating board 316 attached to a floater 318 coversthe ink liquid in order to increase intensity of the reflected wave fromthe ink liquid surface. The floating board 316 is preferably formed ofmaterial which has high acoustic impedance and is ink-resistant such asceramic or the like.

[0138]FIG. 20 and FIG. 21 shows a detail and equivalent circuit of anactuator 106, which is an embodiment of the piezoelectric device of thepresent invention. The actuator explained herein is used at least forthe method which detects the liquid consumption status in the liquidcontainer by detecting a change in acoustic impedance. Especially, theactuator is used for the method which detects the liquid consumptionstatus in the liquid container by detecting at least the change inacoustic impedance by detecting the resonant frequency from residualvibration. FIG. 20(A) is an enlarged plan view of the actuator 106. FIG.20(B) shows a B-B cross-section of the actuator 106. FIG. 20(C) shows aC-C cross-section of the actuator 106. FIG. 21(A) and FIG. 21(B) showsan equivalent circuit of the actuator 106. Each of FIG. 21(C) and FIG.21(D) shows the actuator 106 and around the actuator 106, and theequivalent circuit of the actuator 106 when an ink is filled in the inkcartridge. FIG. 21(E) and FIG. 21(F) shows the actuator 106 and aroundthe actuator 106, and the equivalent circuit of the actuator 106 whenthere is no ink in the ink cartridge.

[0139] The actuator 106 includes a base plate 178, a vibrating plate176, a piezoelectric layer 160, an upper electrode 164 and a lowerelectrode 166, an upper electrode terminal 168, a lower electrodeterminal 170, and a supplementary electrode 172. The base plate 178 hasa circular shape opening 161 on approximately its center. The vibratingplate 176 is provided on one of the face, which is called as “rightside” in following, of the base plate 178 such as to cover the opening161. The piezoelectric layer 160 is disposed on right side of thesurface of the vibrating plate 176. The upper electrode 164 and thelower electrode 166 sandwich the piezoelectric layer 160 from bothsides. The upper electrode terminal 168 connects to the upper electrode164 electrically. The lower electrode terminal 170 connects to the lowerelectrode 166 electrically. The supplementary electrode 172 is disposedbetween the upper electrode 164 and the upper electrode terminal 168 andconnects both of the upper electrode 164 and the upper electrodeterminal 168. Each of the piezoelectric layer 160, upper electrode 164,and the lower electrode 166 has a circular portion as its main portion.Each of the circular portion of the piezoelectric layer 160, the upperelectrode 164, and the lower electrode 166 form a piezoelectric element.

[0140] The vibrating plate 176 is formed on the right side of thesurface of the base plate 178 to cover the opening 161. The cavity 162is formed by the portion of the vibrating plate 176, which faces theopening 161, and the opening 161 of the on the surface of the base plate178. The face of the base plate 178 which is opposite side of thepiezoelectric element, called as “back side” in following, is faced withthe liquid container side. The cavity 162 is constructed such that thecavity 162 contacts with liquid. The vibrating plate 176 is mounted onthe base plate 178 such that the liquid does not leak to the right sideof the surface of the base plate 178 even if the liquid enters insidethe cavity 162.

[0141] The lower electrode 166 is located on the right side of thevibrating plate 176, that is, opposite side against the liquidcontainer. The lower electrode 166 is provided on the vibrating plate176 such that the center of the circular portion of the lower electrode166, which is a main portion of the lower electrode 166, and the centerof the opening 161 substantially matches. The area of the circularportion of the lower electrode 166 is set to be smaller than the area ofthe opening 161. The piezoelectric layer 160 is formed on the right sideof the surface of the lower electrode 166 such that the center of thecircular portion and the center of the opening 161 substantially match.The area of the circular portion of the piezoelectric layer 160 is setto be smaller than the area of the opening 161 and larger than the areaof the circular portion of the lower electrode 166.

[0142] The upper electrode 164 is formed on the right side of thesurface of the piezoelectric layer 160 such that the center of thecircular portion, which is a piezoelectric layer 160, and the center ofthe opening 161 substantially match. The area of the circular portion ofthe upper electrode 164 is set to be smaller than the area of thecircular portion of the opening 161 and the piezoelectric layer 160 andlarger than the area of the circular portion of the lower electrode 166.

[0143] Therefore, the main portion of the piezoelectric layer 160 has astructure to be sandwiched by the main portion of the upper electrode164 and the main portion of the lower electrode each from right sideface and back side face, and thus the main portion of the piezoelectriclayer 160 can effectively drive and deform the piezoelectric layer 160.The circular portion, which is a main portion of each of thepiezoelectric layer 160, the upper electrode 164, and the lowerelectrode 166, forms the piezoelectric element in the actuator 106. Asexplained above, the electric element contacts with the vibrating plate.Within the circular portion of the upper electrode 164, circular portionof the piezoelectric layer 160, the circular portion of the lowerelectrode, and the opening 161, the opening 161 has the largest area. Bythis structure, the vibrating region which actually vibrates within thevibrating plate is determined by the opening 161. Furthermore, each ofthe circular portion of the upper electrode 164 and the circular portionof the piezoelectric layer 160 and the circular portion of the lowerelectrode has smaller area than the area of the opening 161, Thevibrating plate becomes easily vibrate. Within the circular portion ofthe lower electrode 166 and the circular portion of the upper electrode164 which connects to the piezoelectric layer 160 electrically, thecircular portion of the lower electrode 166 is smaller than the circularportion of the upper electrode 164. Therefore, the circular portion ofthe lower electrode 166 determines the portion which generates thepiezoelectric effect within the piezoelectric layer 160.

[0144] The center of the circular portion of the piezoelectric layer160, the upper electrode 164, and the lower electrode 166, which formthe piezoelectric element, substantially match to the center of theopening 161. Moreover, the center of the circular shape opening 161,which determines the vibrating section of the vibrating plate 176, isprovided on the approximately center of the actuator 106. Therefore, thecenter of the vibrating section of the actuator 106 matches to thecenter of the actuator 106. Because the main portion of thepiezoelectric element and the vibrating section of the vibrating plate176 have a circular shape, the vibrating section of the actuator 106 issymmetrical about a center of the actuator 106.

[0145] Because the vibrating section is symmetrical about a center ofthe actuator 106, the excitation of the unnecessary vibration occurredowing to the asymmetric structure can be prevented. Therefore, theaccuracy of detecting the resonant frequency increases. Furthermore,because the vibrating section is symmetric about the center of theactuator 106, the actuator 106 is easy to manufacture, and thus theunevenness of the shape for each of the piezoelectric element can bedecreased. Therefore, the unevenness of the resonant frequency for eachof the piezoelectric element 174 decreases. Furthermore, because thevibrating section has an isotropic shape, the vibrating section isdifficult to be influenced by the unevenness of the fixing during thebonding process. That is, the vibrating section is bonded to the liquidcontainer uniformly. Therefore, the actuator 106 is easy to assemble tothe liquid container.

[0146] Furthermore, because the vibrating section of the vibrating plate176 has a circular shape, the lower resonant mode, for example, theprimary resonant mode dominates on the resonant mode of the residualvibration of the piezoelectric layer 160, and thus the single peakappears on the resonant mode. Therefore, the peak and the noise can bedistinguished clearly so that the resonant frequency can be clearlydetected. Furthermore, the accuracy of the detection of the resonantfrequency can be further increased by enlarge the area of the vibratingsection of the circular shape vibrating plate 176 because the differenceof the amplitude of the counter electromotive force and the differenceof the amplitude of the resonant frequency occurred by whether theliquid exists inside the liquid container increase.

[0147] The displacement generated by the vibration of the vibratingplate 176 is larger than the displacement generated by the vibration ofthe base plate 178. The actuator 106 has a two layers structure that isconstituted by the base plate 178 having a small compliance which meansit is difficult to be displaced by the vibration, and the vibratingplate 176 having a large compliance which means it is easy to bedisplaced by the vibration. By this two layers structure, the actuator106 can be reliably fixed to the liquid container by the base plate 178and at the same time the displacement of the vibrating plate 176 by thevibration can be increased. Therefore, the difference of the amplitudeof the counter electromotive force and the difference of the amplitudeof the resonant frequency depended on whether the liquid exists insidethe liquid container increases, and thus the accuracy of the detectionof the resonant frequency increases. Furthermore, because the complianceof the vibrating plate 176 is large, the attenuation of the vibrationdecreases so that the accuracy of the detection of the resonantfrequency increases. The node of the vibration of the actuator 106locates on the periphery of the cavity 162, that is, around the marginof the opening 161.

[0148] The upper electrode terminal 168 is formed on the right side ofthe surface of the vibrating plate 176 to be electrically connected tothe upper electrode 164 through the supplementary electrode 172. Thelower electrode terminal 170 is formed on the right side of the surfaceof the vibrating plate 176 to be electrically connected to the lowerelectrode 166. Because the upper electrode 164 is formed on the rightside of the piezoelectric layer 160, there is a difference in depth thatis equal to the sum of the thickness of the piezoelectric layer 160 andthe thickness of the lower electrode 166 between the upper electrode 164and the upper electrode terminal 168. It is difficult to fill thisdifference in depth only by the upper electrode 164, and even it ispossible to fill the difference in depth by the upper electrode 164, theconnection between the upper electrode 164 and the upper electrodeterminal 168 becomes weak so that the upper electrode 164 will be cutoff. Therefore, this embodiment uses the supplementary electrode 172 asa supporting member to connects the upper electrode 164 and the upperelectrode terminal 168. By this supplementary electrode 172, both of thepiezoelectric layer 160 and the upper electrode 164 are supported by thesupplementary electrode 172, and thus the upper electrode 164 can havedesired mechanical strength, and also the upper electrode 164 and theupper electrode terminal 168 can be firmly connected.

[0149] The piezoelectric element and the vibrating section which facesto the piezoelectric element within the vibrating plate 176 constitutethe vibrating section which actually vibrates in the actuator 106.Moreover, it is preferable to form the actuator 106 in one body byfiring together the member included in the actuator 106. By forming theactuator 106 as one body, the actuator 106 becomes easy to be handled.Further, the vibration characteristic increases by increasing thestrength of the base plate 178. That is, by increasing the strength ofthe base plate 178, only the vibrating section of the actuator 106vibrates, and the portion other than the vibrating section of theactuator 106 does not vibrates. Furthermore, the prevention of thevibration of the portion other than the vibrating section of theactuator 106 can be achieved by increasing the strength of the baseplate 178 and at the same time forming the actuator 106 as thinner andsmaller as possible and forming the vibrating plate 176 as thinner aspossible.

[0150] It is preferable to use lead zirconate titanate (PZT), leadlanthanum zirconate titanate (PLZT), or piezoelectric membrane withoutusing lead as a material for the piezoelectric layer 160. It ispreferable to use zirconia or aluminum as a material of the base plate178. Furthermore, it is preferable to use same material as base plate178 for a material of vibrating plate 176. The metal such as gold,silver, copper, platinum, aluminum, and nickel having a electricalconductivity can be used for the material of the upper electrode 164,the lower electrode 166, the upper electrode terminal 168, and the lowerelectrode terminal 170.

[0151] The actuator 106 constructed as explained above can be applied tothe container which contains liquid. For example, the actuator 106 canbe mounted on an ink cartridge used for the ink jet recording apparatus,an ink tank, or a container which contains washing liquid to wash therecording head.

[0152] The actuator 106 shown in the FIG. 20 and FIG. 21 is mounted onthe predetermined position on the liquid container so that the cavity162 can contact with the liquid contained inside the liquid container.When the liquid container is filled with liquid sufficiently, the insideand outside of the cavity 162 is filled with liquid. On the other hand,if the liquid inside liquid container consumed and the liquid leveldecreased under the mounting position of the actuator, there areconditions that liquid does not exit inside the cavity 162 or thatliquid is remained only in the cavity 162 and air exits on outside thecavity 162. The actuator 106 detects at least the difference in theacoustic impedance occurred by this change in condition. By thisdetection of the difference in acoustic impedance, the actuator 106 candetects the whether the liquid is sufficiently filled in the liquidcontainer or liquid is consumed more than predetermined level.Furthermore, the actuator 106 can detects the type of the liquid insidethe liquid container.

[0153] The principle of the detection of the liquid level by theactuator will be explained.

[0154] To detect the acoustic impedance of a medium, an impedancecharacteristic or an admittance characteristic is measured. To measurethe impedance characteristic or the admittance characteristic, forexample, transmission circuit can be used. The transmission circuitapplies a constant voltage on the medium and measure a current flowthrough the medium with changing a frequency. The transmission circuitprovides a constant current to the medium and measures a voltage appliedon the medium with changing a frequency. The change in current value andthe voltage value measured at the transmission circuit shows the changein acoustic impedance. Furthermore, the change in a frequency fm, whichis a frequency when the current value or the voltage value becomesmaximum or minimum, also shows the change in acoustic impedance.

[0155] Other than method shown above, the actuator can detects thechange in the acoustic impedance of the liquid using the change only inthe resonant frequency. The piezoelectric element, for example, can beused in a case of using the method of detecting the resonant frequencyby measuring the counter electromotive force generated by the residualvibration, which is remained in the vibrating section after thevibration of the vibrating section of the actuator, as a method of usingthe change in the acoustic impedance of the liquid. The piezoelectricelement is element which generates the counter electromotive force byresidual vibration remained in the vibrating section of the actuator.The magnitude of the counter electromotive force changes with theamplitude of the vibrating section of the actuator. Therefore, thelarger the amplitude of the vibrating section of the actuator, theeasier to detect the resonant frequency. Moreover, depends on thefrequency of the residual vibration at the vibrating section of theactuator, the period, on which the magnitude of the counterelectromotive force changes, changes. Therefore, the frequency of thevibrating section of the actuator corresponds to the frequency of thecounter electromotive force. Here, the resonant frequency means thefrequency when the vibrating section of the actuator and the medium,which contacts to the vibrating section, are in a resonant condition.

[0156] To obtain the resonant frequency fs, the waveform obtained bymeasuring the counter electromotive force when the vibrating section andthe medium are in resonant condition is Fourier transformed. Because thevibration of the actuator is not a displacement for only one direction,but the vibration involves the deformation such as deflection andextension, the vibration has various kinds of frequency including theresonant frequency fs. Therefore, the resonant frequency fs is judged byFourier transforming the waveform of the counter electromotive forcewhen the piezoelectric element and the medium are in the resonantcondition and then specifying the most dominating frequency components.

[0157] The frequency fm is a frequency when the admittance of the mediumis maximum or the impedance is minimum. The frequency fm is differentfrom the resonant frequency fs with little value because of thedielectric loss and the mechanical loss. However, the frequency fm isgenerally used as substitution for resonant frequency because it needstime for deriving the resonant frequency fs from the frequency fm whichis actually measured. By inputting output of the actuator 106 to thetransmission circuit, the actuator 106 can at least detect the acousticimpedance.

[0158] It is proved by the experiment that there is almost nodifferences with the resonant frequency obtained by the method, whichmeasures the frequency fm by measuring the impedance characteristic andadmittance characteristic of the medium, and the method, which measuresthe resonant frequency fs by measuring the counter electromotive forcegenerated by the residual vibration at the vibrating section of theactuator.

[0159] The vibrating region of the actuator 106 is a portion whichconstitutes the cavity 162 that is determined by the opening 161 withinthe vibrating plate 176. When liquid is sufficiently filled in theliquid container, liquid is filled in the cavity 162, and the vibratingregion contacts with liquid inside the liquid container. When liquiddoes not exists in the liquid container sufficiently, the vibratingregion contacts with the liquid which is remained in the cavity insidethe liquid container, or the vibrating region does not contacts with theliquid but contacts with the gas or vacuum.

[0160] The cavity 162 is provided on the actuator 106 of the presentinvention, and it can be designed that the liquid inside the liquidcontainer remains in the vibrating region of the actuator 106 by thecavity 162. The reason will be explained as follows.

[0161] Depends on the mounting position and mounting angle of theactuator 106 on the liquid container, there is a case in which theliquid attaches to the vibrating region of the actuator even the liquidlevel in the liquid container is lower than the mounting position of theactuator. When the actuator detects the existence of the liquid onlyfrom the existence of the liquid on the vibrating region, the liquidattached to the vibrating region of the actuator prevents the accuratedetection of the existence of the liquid. For example, If the liquidlevel is lower than the mounting position of the actuator, and the dropof the liquid attaches to the vibrating region by the waving of theliquid caused by the shaking of the liquid container caused by themovement of the carriage, the actuator 106 will misjudges that there isenough liquid in the liquid container. In this way, the malfunction canbe prevented by using the actuator having cavity.

[0162] Furthermore, as shown in FIG. 21(E), the case when the liquiddoes not exit in the liquid container and the liquid of the liquidcontainer remains in the cavity 162 of the actuator 106 is set as thethreshold value of the existence of the liquid. That is, if the liquiddoes not exist around the cavity 162, and the amount of the liquid inthe cavity is smaller than this threshold value, it is judged that thereis no ink in the liquid container. If the liquid exist around the cavity162, and the amount of the liquid is larger than this threshold value,it is judged that there is ink in the liquid container. For example,when the actuator 106 is mounted on the side wall of the liquidcontainer, it is judged that there is no ink in the liquid containerwhen the liquid level inside the liquid container is lower than themounting position of the actuator 106, and it is judged that there isink inside the liquid container when the liquid level inside the liquidcontainer is higher than the mounting position of the actuator 106. Bysetting the threshold value in this way, the actuator 106 can judge thatthere is no ink in the liquid container even if the ink attaches to thecavity again by shaking of the carriage after the ink in the cavitydisappears because the amount of the ink attaches to the cavity againdoes not exceed the threshold value.

[0163] The operation and the principle of detecting the liquid conditionof the liquid container from the resonant frequency of the medium andthe vibrating section of the actuator 106 obtained by measuring thecounter electromotive force will be explained reference to FIG. 20 andFIG. 21. A voltage is applied on each of the upper electrode 164 and thelower electrode 166 through the upper electrode terminal 168 and thelower electrode terminal 170. The electric field is generated on theportion of the piezoelectric layer 160 where the piezoelectric layer 160is sandwiched by the upper electrode 164 and the lower electrode 166. Bythis electric field, the piezoelectric layer 160 deforms. By thedeformation of the piezoelectric layer 160, the vibrating region withinthe vibrating plate 176 deflects and vibrates. For some period after thedeformation of the piezoelectric layer 160, the vibration withdeflection remains in the vibrating section of the actuator 106.

[0164] The residual vibration is a free oscillation of the vibratingsection of the actuator 106 and the medium. Therefore, the resonantcondition between the vibrating section and the medium can be easilyobtained by applying the voltage of a pulse wave or a rectangular waveon the piezoelectric layer 160. Because the residual vibration vibratesthe vibrating section of the actuator 106, the residual vibration alsodeforms the piezoelectric layer 160. Therefore, the piezoelectric layer160 generates the counter electromotive force. This counterelectromotive force is detected through the upper electrode 164, thelower electrode 166, the upper electrode terminal 168, and the lowerelectrode terminal 170. Because the resonant frequency can be specifiedby this detected counter electromotive force, the liquid consumptionstatus in the liquid container can be detected.

[0165] Generally, the resonant frequency fs can be expressed asfollowing.

fs=1/(2*π*(M*Cact)^(1/2)  (1)

[0166] where M denotes the sum of an inertance of the vibrating sectionMact and an additional inertance M′; Cact denotes a compliance of thevibrating section.

[0167]FIG. 20(C) shows a cross section of the actuator 106 when the inkdoes not exist in the cavity in the present embodiment. FIG. 21(A) andFIG. 21(B) shows the equivalent circuit of the vibrating section of theactuator 106 and the cavity 162 when the ink does not exist in thecavity.

[0168] The Mact is obtained by dividing the product of the thickness ofthe vibrating section and the density of the vibrating section by thearea of the vibrating section. Furthermore, as shown in the FIG. 21(A),the Mact can be expressed as following in detail.

Mact=Mpzt+Melectrode1+Melectrode2+Mvib  (2)

[0169] Here, Mpzt is obtained by dividing the product of the thicknessof the piezoelectric layer 160 in the vibrating section and the densityof the piezoelectric layer 160 by the area of the piezoelectric layer160. Melectrode1 is obtained by dividing the product of the thickness ofthe upper electrode 164 in the vibrating section and the density of theupper electrode 164 by the area of the upper electrode 164. Melectrode2is obtained by dividing the product of the thickness of the lowerelectrode 166 in the vibrating section and the density of the lowerelectrode 166 by the area of the lower electrode 166. Mvib is obtainedby dividing the product of the thickness of the vibrating plate 176 inthe vibrating section and the density of the vibrating plate 176 by thearea of the vibrating region of the vibrating plate 176. However each ofthe size of the area of the vibrating region of the piezoelectric layer160, the upper electrode 164, the lower electrode 166, and vibratingplate 176 have a relationship as shown above, the difference among eachof the area of the vibrating region is prefer to be microscopic toenable the caculation of the Mact from the thickness, density, and areaas whole of the vibrating section. Moreover, it is preferable that theportion other than the circular portion which is a main portion of eachof the piezoelectric layer 160, the upper electrode 164, and the lowerelectrode 166 is microscopic so that it can be ignored compared to themain portion. Therefore, Mact is sum of the inertance of the each of thevibrating region of the upper electrode 164, the lower electrode 166,the piezoelectric layer 160, and the vibrating plate 176 in the actuator106. Moreover, the compliance Cact is a compliance of the portion formedby the each of the vibrating region of the upper electrode 164, thelower electrode 166, the piezoelectric layer 160, and the vibratingplate 176.

[0170]FIG. 21(A), FIG. 21(B), FIG. 21(D), and FIG. 21(F) show theequivalent circuit of the vibrating section of the actuator 106 and thecavity 162. In these equivalent circuits, Cact shows a compliance of thevibrating section of the actuator 106. Each of the Cpzt, Celectrode1,Celectrode2, and Cvib shows the compliance of the vibrating section ofthe piezoelectric layer 160, the upper electrode 164, the lowerelectrode 166, and the vibrating plate 176. Cact can be shown asfollowing equation.

1/Cact=(1/Cpzt)+(1/Celectrode1)+(1/Celectrode2)+(1/Cvib)  (3)

[0171] From the equation (2) and (3), FIG. 21(A) can be expressed asFIG. 21(B).

[0172] The compliance Cact shows the volume which can accept the mediumby the deformation generated by the application of the pressure on theunit area of the vibrating section. In other words, the compliance Cactshows the easiness to be deformed.

[0173]FIG. 21(C) shows the cross section of the actuator 106 when theliquid is sufficiently filled in the liquid container, and the peripheryof the vibrating region of the actuator 106 is filled with the liquid.The M′max shown in FIG. 21(C) shows the maximum value of the additionalinertance when the liquid is sufficiently filled in the liquidcontainer, and the periphery of the vibrating region of the actuator 106is filled with the liquid. The M′max can be expressed as

M′max=(π*ρ/(2*k ³))*(2*(2*k*a)³/(3*π))/(π*a ²)²  (4)

[0174] where a denotes the radius of the vibrating section; ρ denotesthe density of the medium; and k denotes the wave number. The equation(4) applies when the vibrating region of the actuator 106 is circularshape having the radius of “a”. The additional inertance M′ shows thequantity that the mass of the vibrating section is increased virtuallyby the effect of the medium which exists around the vibrating section.

[0175] As shown in FIG. 4, the M′max can changes significantly by theradius of the vibrating section “a” and the density of the medium ρ.

[0176] The wave number k can be expressed by following equation.

k=2*π*fact/c  (5)

[0177] where fact denotes the resonant frequency of the vibratingsection when the liquid does not contact with the vibrating section; andc denotes the speed of the sound propagate through the medium.

[0178]FIG. 21(D) shows an equivalent circuit of the vibrating section ofthe actuator 106 and the cavity 162 as in the case of FIG. 21(C) whenthe liquid is sufficiently filled in the liquid container, and theperiphery of the vibrating region of the actuator 106 is filled with theliquid.

[0179]FIG. 21(E) shows the cross section of the actuator 106 when theliquid in the liquid container is consumed, and there is no liquidaround the vibrating region of the actuator 106, and the liquid remainsin the cavity 162 of the actuator 106. The equation (4) shows themaximum inertance M′max determined by such as the ink density ρ when theliquid container is filled with the liquid. On the other hand, if theliquid in the liquid container is consumed and liquid existed around thevibrating section of the actuator 106 becomes gas or vacuum with theliquid remaining in the cavity 162, the M′ can be expressed as followingequation.

M′=ρ*t/S  (6)

[0180] where t denotes the thickness of the medium related to thevibration; S denotes the area of the vibrating region of the actuator106. If this vibrating region is circular shape having a radius of “a”,the S can be shown as S=π*a². Therefore, the additional inertance M′follows the equation (4) when the liquid is sufficiently filled in theliquid container, and the periphery of the vibrating region of theactuator 106 is filled with the liquid. The additional inertance M′follows the equation (6) when the liquid in the liquid container isconsumed, and there is no liquid exits around the vibrating region ofthe actuator 106, and the liquid is remained in the cavity 162.

[0181] Here, as shown in FIG. 21(E), let the additional inertance M′,when the liquid in the liquid container is consumed, and there is noliquid exits around the vibrating region of the actuator 106, and theliquid is remained in the cavity 162, as M′cav to distinguish with theadditional inertance M′max, which is the additional inertance when theperiphery of the vibrating region of the actuator 106 is filled with theliquid.

[0182]FIG. 21(F) shows an equivalent circuit of the vibrating section ofthe actuator 106 and the cavity 162 in the case of FIG. 21(E) when theliquid in the liquid container is consumed, and there is no liquidaround the vibrating region of the actuator 106, and the liquid remainsin the cavity 162 of the actuator 106.

[0183] Here, the parameters related to the status of the medium aredensity of the medium ρ and the thickness of the medium t in equation(6). When the liquid is sufficiently filled in the liquid container, theliquid contacts with the vibrating section of the actuator 106. When theliquid is insufficiently filled in the liquid container, the liquid isremained in the cavity, or the gas or vacuum contacts with the vibratingsection of the actuator 106. If let the additional inertance during theprocess of the shifting from the M′max of FIG. 21(C) to the M′var ofFIG. 21(E) when the liquid around the actuator 106 is consumed, becausethe thickness of the medium t changes according to the containing statusof the liquid in the liquid container, the additional inertance M′varchanges, and resonant frequency also changes. Therefore, the existenceof the liquid in the liquid container can be detected by specify theresonant frequency. Here, if let t=d, as shown in FIG. 21(E) and usingthe equation (6) to express the m′cav, the equation (7) can be obtainedby substituting the thickness of the cavity “d” into the “t” in theequation (6).

M′cav=ρ*d/S  (7)

[0184] Moreover, if the medium are different types of liquid with eachother, the additional inertance M′ changes and resonant frequency fsalso changes because the density ρ is different according to thedifference of the composition. Therefore, the types of the liquid can bedetected by specifying the resonant frequency fs. Moreover, when onlyone of the ink or air contacts with the vibrating section of theactuator 106, and the ink and air is not existing together, thedifference in M′ can be detected by calculating the equation (4).

[0185]FIG. 22(A) is a graph which shows the relationship between the inkquantity inside the ink tank and the resonant frequency fs of the inkand the vibrating section. Here, the case for the ink will be explainedas an example of the liquid. The vertical axis shows the resonantfrequency fs, and the horizontal axis shows the ink quantity. When theink composition is constant, the resonant frequency increases accordingto the decreasing of the ink quantity.

[0186] When ink is sufficiently filled in the ink container, and ink isfilled around the vibrating region of the actuator 106, the maximumadditional inertance M′max becomes the value shown in the equation (4).When the ink is consumed, and there is no ink around the vibratingregion of the actuator 106, and the ink remains in the cavity 162, theadditional inertance M′var is calculated by the equation (6) based onthe thickness of the medium t. Because the “t” used in the equation (6)is the thickness of the medium related to the vibration, the processduring which the ink is consumed gradually can be detected by formingthe “d” (refer to FIG. 20(B)) of the cavity 162 of the actuator 106 assmall as possible, that is, forming the thickness of the base plate 178as sufficiently thinner as possible (refer to FIG. 21(C)). Here, let thet-ink as the thickness of the ink involved with the vibration, andt-ink-max as the t-ink when the additional inertance is M′max. Forexample, the actuator 106 is mounted on the bottom of the ink cartridgehorizontally to the surface of the ink. If ink is consumed, and the inklevel becomes lower than the height t-ink-max from the actuator 106, theM′var gradually changes according to the equation (6), and the resonantfrequency fs gradually changes according to the equation (1). Therefore,until the ink level is within the range of “t”, the actuator 106 cangradually detect the ink consumption status.

[0187] Furthermore, by enlarge or lengthen the vibrating section of theactuator 106 and arrange the actuator 106 along a lengthwise direction,the “S” in the equation (6) changes according to the change of ink levelwith ink consumption. Therefore, the actuator 106 can detect the processwhile the ink is gradually consumed. For example, the actuator 106 ismounted on the side wall of the ink cartridge perpendicularly to the inksurface. When the ink is consumed and the ink level reaches to thevibrating region of the actuator 106, because the additional inertanceM′ decreases with the decreasing of the ink level, the resonantfrequency fs gradually increases according to the equation (1).Therefore, unless the ink level is within the range of the radius 2 a ofthe cavity 162 (refer to FIG. 21(C)), the actuator 106 can graduallydetect the ink consumption status.

[0188] The curve X in FIG. 22(A) shows the relationship between the inkquantity contained inside of the ink tank and the resonant frequency fsof the ink and the vibrating section when the vibrating region of theactuator 106 is formed sufficiently large or long. It can be understandthat the resonant frequency fs of the ink and vibrating sectiongradually changes with the decrease of the ink quantity inside the inktank.

[0189] In detail, the case when the actuator 106 can detect the processof the gradual consumption of the ink is the case when the liquid andgas having different density with each other are existed together andalso involved with vibration. According to the gradual consumption ofthe ink, the liquid decreases with increasing of the gas in the mediuminvolved with the vibration around the vibrating region of the actuator106. For example, the case when the actuator 106 is mounted on the inkcartridge horizontally to the ink surface, and t-ink is smaller than thet-ink-max, the medium involved with the vibration of the actuator 106includes both of the ink and the gas. Therefore, the following equation(8) can be obtained if let the area of the vibrating region of theactuator 106 as S and express the status when the additional inertanceis below M′max in the equation (4) by additional mass of the ink and thegas.

M′=M′air+M′ink=ρair*t-air/S+ρink*t-ink/S  (8)

[0190] where M′max is an inertance of an air; M′ink is an inertance ofan ink; ρair is a density of an air; ρink is a density of an ink; t-airis the thickness of the air involved with the vibration; and t-ink isthe thickness of the ink involved with the vibration. In case when theactuator 106 is mounted on the ink cartridge approximately horizontallyto the ink surface, the t-air increases and the t-ink decreases with theincrease of the gas and the decrease of the ink within the mediuminvolved with the vibration around the vibrating region of the actuator106. The additional inertance M′ gradually decreases, and the resonantfrequency gradually increases by above changes of the t-air and thet-ink. Therefore, the ink quantity remained inside the ink tank or theink consumption quantity can be detected. The equation (7) depends onlyon the density of the liquid because of the assumption that the densityof the air is small compare to the density of the liquid so that thedensity of the air can be ignored.

[0191] When the actuator 106 is provided on the ink cartridgesubstantially perpendicular to the ink surface, the status can beexpressed as the equivalent circuit, not shown in the figure, on whichthe region, where the medium involved with the vibration of the actuator106 is ink only, and the region, where the medium involved with thevibration of the actuator 106 is gas, can be expressed as parallelcircuit. If let the area of the region where the medium involved withthe vibration of the actuator 106 is ink only as Sink, and let the areaof the region where the medium involved with the vibration of theactuator 106 is gas only as Sair, the following equation (9) can beobtained.

1/M′=1/M′air+1/M′ink=Sair/(ρair*t-air)+Sink/(ρink*t-ink)  (9)

[0192] The equation (9) can be applied when the ink is not held in thecavity of the actuator 106. The case when the ink is held in the cavitycan be calculated using the equation (7), (8), and (9).

[0193] In the case when the thickness of the base plate 178 is thick,that is, the depth of the cavity 162 is deep and d is comparativelyclose to the thickness of the medium t-ink-max, or in the case whenusing actuator having a very small vibrating region compared to heightof the liquid container, the actuator does not detect the process of thegradual decrease of the ink but actually detects whether the ink levelis higher or lower than the mounting position of the actuator. In otherwords, the actuator detects the existence of the ink at the vibratingregion of the actuator. For example, the curve Y in FIG. 22(A) shows therelationship between the ink quantity in the ink tank and the resonantfrequency fs of the vibrating section when the vibrating section issmall circular shape. The curve Y shows that the resonant frequency fsof the ink and the vibrating section changes extremely during the rangeof change of ink quantity Q, which corresponds to the status before andafter the ink level in the ink tank passes the mounting position of theactuator. By this changes of the resonant frequency fs, it can bedetected whether the ink quantity remained in the ink tank is more thanthe predetermined quantity.

[0194] The method of using the actuator 106 for detecting the existenceof the liquid is more accurate than the method which calculates thequantity of ink consumption by the software because the actuator 106detects the existence of the ink by directly contacting with the liquid.Furthermore, the method using an electrode to detects the existence ofthe ink by conductivity is influenced by the mounting position to theliquid container and the ink type, but the method using the actuator 106to detects the existence of the liquid does not influenced by themounting position to the liquid container and the ink type. Moreover,because both of the oscillation and detection of the existence of theliquid can be done by the single actuator 106, the number of the sensormounted on the liquid container can be reduced compare to the methodusing separate sensor for oscillation and the detection of the existenceof the liquid. Therefore, the liquid container can be manufactured at alow price. Furthermore, the sound generated by the actuator 106 duringthe operation of the actuator 106 can be reduced by setting thevibrating frequency of the piezoelectric layer 160 out of the audiofrequency.

[0195]FIG. 22(B) shows the relationship between the density of the inkand the resonant frequency fs of the ink and the vibrating section ofthe curve Y shown in FIG. 22(A). Ink is used as an example of liquid. Asshown in FIG. 22(B), when ink density increases, the resonant frequencyfs decreases because the additional inertance increases. In other words,the resonant frequency fs are different with the types of the ink.Therefore, By measuring the resonant frequency fs, it can be confirmedwhether the ink of a different density has been mixed together duringthe re-filling of the ink to the ink tank.

[0196] Therefore, the actuator 106 can distinguish the ink tank whichcontains the different type of the ink.

[0197] The condition when the actuator 106 can accurately detects thestatus of the liquid will be explained in detail in following. The caseis assumed that the size and the shape of the cavity is designed so thatthe liquid can be remained in the cavity 162 of the actuator 106 evenwhen the liquid inside the liquid container is empty. The actuator 106can detect the status of the liquid even when the liquid is not filledin the cavity 162 if the actuator 106 can detect the status of theliquid when the liquid is filled in the cavity 162.

[0198] The resonant frequency fs is a function of the inertance M. Theinertance M is a sum of the inertance of the vibrating section Mact andthe additional inertance M′. Here, the additional inertance M′ has therelationship with the status of the liquid. The additional inertance M′is a quantity of a virtual increase of a mass of the vibrating sectionby the effect of the medium existed around the vibrating section. Inother words, the additional inertance M′ is the amount of increase ofthe mass of the vibrating section which is increased by the vibration ofthe vibrating section that virtually absorbs the medium.

[0199] Therefore, when the M′cav is larger than the M′max in theequation (4), all the medium which is virtually absorbed is the liquidremained in the cavity 162. Therefore, the status when the M′cav islarger than the M′max is same with the status that the liquid containeris fill with liquid. The resonant frequency fs does not change becausethe M′ does not change in this case. Therefore, the actuator 106 cannotdetect the status of the liquid in the liquid container.

[0200] On the other hand, if the M′cav is smaller than the M′max in theequation (4), the medium which is virtually absorbed is the liquidremained in the cavity 162 and the gas or vacuum in the liquidcontainer. In this case, because the M′ changes, which is different withthe case when the liquid is filled in the liquid container, the resonantfrequency fs changes. Therefore, the actuator 106 can detect the statusof the liquid in the liquid container.

[0201] The condition whether the actuator 106 can accurately detect thestatus of the liquid is that the M′cav is smaller than the M′max whenthe liquid is remained in the cavity 162 of the actuator 106, and theliquid container is empty. The condition M′max>M′cav, on which theactuator 106 can accurately detect the status of the liquid, does notdepend on the shape of the cavity 162.

[0202] Here, the M′cav is the mass of the liquid of the volume which issubstantially equal to the volume of the cavity 162. Therefore, thecondition, which can detect the status of the liquid accurately, can beexpressed as the condition of the volume of the cavity 162 from theinequality M′max>M′cav. For example, if let the radius of the opening161 of the circular shaped cavity 162 as “a” and the thickness of thecavity 162 as “d”, then the following inequality can be obtained.

M′max>ρ*d/πa ²  (10)

[0203] By expanding the inequality (10), the following condition can beobtained.

a/d>3*π/8  (11)

[0204] The inequality (10) and (11) are valid only when the shape of thecavity 162 is circular. By using the equation when the M′max is notcircular and substituting the area πa² with its area, the relationshipbetween the dimension of the cavity such as a width and a length of thecavity and the depth can be derived.

[0205] Therefore, if the actuator 106 has the cavity 162 which has theradius of the opening 161 “a” and the depth of the cavity “d” thatsatisfy the condition shown in inequality (11), the actuator 106 candetect the liquid status without malfunction even when the liquidcontainer is empty and the liquid is remained in the cavity 162.

[0206] Because the additional inertance influences the acousticimpedance characteristic, it can be said that the method of measuringthe counter electromotive force generated in actuator 106 by residualvibration measures at least the change of the acoustic impedance.

[0207] Furthermore, according to the present embodiment, the actuator106 generates the vibration, and the actuator 106 itself measures thecounter electromotive force in actuator 106 which is generated by theresidual vibration remained after the vibration of the actuator 106.However, it is not necessary for the vibrating section of the actuator106 to provide the vibration to the liquid by the vibration of theactuator 106 itself which is generated by the driving voltage. Even thevibrating section itself does not oscillates, the piezoelectric layer160 deflects and deforms by vibrates together with the liquid, whichcontacts with the vibrating section with some range. This residualvibration generates the counter electromotive force voltage in thepiezoelectric layer 160 and transfer this counter electromotive forcevoltage to the upper electrode 164 and the lower electrode 166. Thestatus of the liquid can be detected using this phenomenon. For example,in case of the ink jet recording apparatus, the status of the ink tankor the ink contained inside the ink tank can be detected using thevibration around the vibrating section of the actuator which isgenerated by the vibration generated by the reciprocating motion of thecarriage to scanning the print head during the printing operation.

[0208]FIG. 23(A) and FIG. 23(B) shows a waveform of the residualvibration of the actuator 106 and the measuring method of the residualvibration. The change of the ink level at the level of the mountingposition of the actuator 106 in the ink cartridge can be detected by thechange in the frequency or the amplitude of the residual vibrationremained after the oscillation of the actuator 106. In FIG. 23(A) andFIG. 23(B), the vertical axis shows the voltage of the counterelectromotive force generated by the residual vibration of the actuator106, and the horizontal axis shows the time. By the residual vibrationof the actuator 106, the waveform of the analog signal of the voltagegenerates as shown in FIG. 23(A) and FIG. 23(B). Then, the analog signalis converted to a digital numerical value corresponding to the frequencyof the signal.

[0209] In the example sown in FIG. 23(A) and FIG. 23(B) the existence ofthe ink is detected by measuring the time during the generation of thefour numbers of pulses from the fourth pulse to the eighth pulse of theanalog signal.

[0210] In detail, after the actuator 106 oscillates, the number of thetimes when the analog signal get across the predetermined referencevoltage form the low voltage side to the high voltage side. The digitalsignal is set to be high while the analog signal becomes fourth countsto the eighth counts, and the time during fourth counts to the eighthcounts is measured by predetermined clock pulse.

[0211]FIG. 23(A) shows the waveform when the ink level is above thelevel of the mounting position of the actuator 106. FIG. 23(B) shows thewaveform when the ink level is below the level of the mounting positionof the actuator 106. Comparing the FIG. 23(A) and FIG. 23(B), the timeof the FIG. 23(A) during the fourth counts to the eighth counts islonger than the time of the FIG. 23(B). In other words, depends on theexistence of the ink, the time from the fourth counts to the eighthcounts is different. By using this difference of the time, theconsumption status of the ink can be detected. The reason to count theanalog signal from the fourth counts is to start the measurement of thetime after the vibration of the actuator 106 becomes stable. It is onlyone of the example of starting the measurement from fourth counts, butmeasurement can be started from the desired counts.

[0212] The signals from the fourth counts to the eighth counts aredetected, and the time from the fourth counts to the eighth counts ismeasured by the predetermined clock pulse. By this measurement, theresonant frequency can be obtained. The clock pulse is prefer to be apulse having a same clock with the clock for controlling such as thesemiconductor memory device which is mounted on the ink cartridge. Itdoes not necessary to measure the time until the eighth counts, but thetime until the desired counts can be measured. In FIG. 23, the time fromthe fourth counts to the eighth counts is measured, however, the timeduring the different interval of the counts also can be detectedaccording to the circuit configuration which detects the frequency.

[0213] For example, when the ink quality is stable and the fluctuationof the amplitude of the peak is small, the resonant frequency can bedetected by detecting the time from the fourth counts to the sixthcounts to increase the speed of detection. Moreover, when the inkquality is unstable and the fluctuation of the amplitude of the pulse islarge, the time from the fourth counts to the twelfth counts can bedetected to detect the residual vibration accurately.

[0214] Furthermore, as other embodiments, the wave number of the voltagewaveform of the counter electromotive force during the predeterminedperiod can be counted. More specifically, after the actuator 106oscillates, the digital signal is set to be high during thepredetermined period, and the number of the times when the analog signalis get across the predetermined reference voltage from the low voltageside to the high voltage side is counted. By measuring the count number,the existence of the ink can be detected.

[0215] Furthermore, it can be known by comparing FIG. 23(A) with FIG.23(B), the amplitude of the waveform of the counter electromotive forceis different when the ink is filled in the ink cartridge and when theink is not existed in the ink cartridge. Therefore, the ink consumptionstatus in the ink cartridge can be detected by measuring the amplitudeof the waveform of the counter electromotive force without calculatingthe resonant frequency. More specifically, for example, a referencevoltage is set between the peak point of the waveform of the counterelectromotive force of the FIG. 23(A) and the peak point of the waveformof the counter electromotive force of the FIG. 23(B). Then, after theactuator 106 oscillates, set the digital signal to be high at thepredetermined time. Then, if the waveform of the counter electromotiveforce get across the reference voltage, it can be judged that there isno ink in the ink cartridge. If the waveform of the counterelectromotive force does not get across the reference voltage, it can bejudged that there is ink in the ink cartridge.

[0216]FIG. 24 shows the manufacturing method of the actuator 106. Aplurality of the actuators 106, four numbers in the case of the FIG. 24,are formed as one body. The actuator 106 shown in FIG. 25 ismanufactured by cutting the plurality of actuator 106, which is formedin one body as shown in FIG. 24, at each of the actuator 106. If theeach of the piezoelectric elements of the each of the plurality of theactuator 106, which is formed in one body as shown in FIG. 24, arecircular shape, the actuator 106 shown in FIG. 20 can be manufactured bycutting the actuator 106, which is formed as one body, at each ofactuator 106. By forming a plurality of the actuator 106 in one body, aplurality of actuator 106 can be manufactured effectively at the sametime, and also the handling during the transportation becomes easy.

[0217] The actuator 106 has a thin plate or a vibrating plate 176, abase plate 178, an elastic wave generating device or piezoelectricelement 174, a terminal forming member or an upper electrode terminal168, and a terminal forming member or a lower electrode terminal 170.The piezoelectric element 174 includes a piezoelectric vibrating plateor a piezoelectric layer 160, an upper electrode 164, and a lowerelectrode 166. The vibrating plate 176 is formed on the top surface ofthe base plate 178, and the lower electrode 166 is formed on the topsurface of the vibrating plate 176. The piezoelectric layer 160 isformed on the top surface of the lower electrode 166, and the upperelectrode 164 is formed on the top surface of the piezoelectric layer160. Therefore, the main portion of the piezoelectric layer 160 isformed by sandwiching the main portion of the piezoelectric layer 160 bythe main portion of the upper electrode 164 and the main portion of thelower electrode 166 from top side and from bottom side.

[0218] A plurality of the piezoelectric element 174, four numbers in thecase of FIG. 24, is formed on the vibrating plate 176. The lowerelectrode 166 is formed on the top surface of the vibrating plate 176.The piezoelectric layer 160 is formed on the top surface of the lowerelectrode 166, and the upper electrode 164 is formed on the top surfaceof the piezoelectric layer 160. The upper electrode terminal 168 and thelower electrode terminal 170 are formed on the end portion of the upperelectrode 164 and the lower electrode 166. The four numbers of theactuator 106 are used separately by cutting each of the actuator 106separately.

[0219]FIG. 25 shows a cross-section of a part of the actuator 106 shownin FIG. 25. The through hole 178 a is formed on the face of the baseplate 178 which faces with the piezoelectric element 174. The throughhole 178 a is sealed by the vibrating plate 176. The vibrating plate 176is formed by the material which has electric insulating characteristicsuch as alumina and zirconium oxide and also possible to be deformedelastically. The piezoelectric element 174 is formed on the vibratingplate 176 to face with the through hole 178 a. The lower electrode 166is formed on the surface of the vibrating plate 176 so as to be extendedto the one direction, left direction in FIG. 26, from the region of thethrough hole 178 a. The upper electrode 164 is formed on the surface ofthe piezoelectric layer 160 so as to be extended to the oppositedirection of the lower electrode 166, which is right direction in FIG.26, from the region of the through hole 178 a. Each of the upperelectrode terminal 168 and the lower electrode terminal 170 is formed onthe surface of the each of supplementary electrode 172 and the lowerelectrode 166, respectively. The lower electrode terminal 170 with thelower electrode 166 electrically, and the upper electrode terminal 168contacts with the upper electrode 164 electrically through thesupplementary electrode 172 to deliver a signal between thepiezoelectric element and the outside of the actuator 106. The upperelectrode terminal 168 and the lower electrode terminal 170 has a heighthigher than the height of the piezoelectric element which is the sum ofthe height of the electrodes and the piezoelectric layer.

[0220]FIG. 27 shows the manufacturing method of the actuator 106 shownin FIG. 24. First, a through hole 940 a is formed on a green sheet 940by perforating the green sheet 940 by a press or laser processing. Thegreen sheet 940 becomes the base plate 178 after the burning process.The green sheet 940 is formed by the material such as ceramic material.Then, a green sheet 941 is laminated on the surface of the green sheet940. The green sheet 941 becomes the vibrating plate 176 after theburning process. The green sheet 941 is formed by the material such aszirconium oxide. Then, a conductive layer 942, the piezoelectric layer160, and a conductive layer 944 is formed on the surface of the greensheet 941 sequentially by the method such as printing. The conductivelayer 942 becomes the lower electrode 166, and the conductive layer 944becomes the upper electrode 164 after the burning process. Next, thegreen sheet 940, the green sheet 941, the conductive layer 942, thepiezoelectric layer 160, and the conductive layer 944 are dried andburned. The spacer member 947 and 948 are provided on the green sheet941 to raising the height of the upper electrode terminal 168 and thelower electrode terminal 170 to be higher than the piezoelectricelement. The spacer member 947 and 948 is formed by printing the samematerial with the green sheet 940 and 941 or by laminating the greensheet on the green sheet 941. By this spacer member 947 and 948, thequantity of the material of the upper electrode terminal 168 and thelower electrode terminal 170, which is a noble metal, can be reduced.Moreover, because the thickness of the upper electrode terminal 168 andthe lower electrode terminal 170 can be reduced, the upper electrodeterminal 168 and the lower electrode terminal 170 can be accuratelyprinted to be a stable height.

[0221] If a connection part 944′, which is connected with the conductivelayer 944, and the spacer member 947 and 948 are formed at the same timewhen the conductive layer 942 is formed, the upper electrode terminal168 and the lower electrode terminal 170 can be easily formed and firmlyfixed. Finally, the upper electrode terminal 168 and the lower electrodeterminal 170 are formed on the end region of the conductive layer 942and the conductive layer 944. During the forming of the upper electrodeterminal 168 and the lower electrode terminal 170, the upper electrodeterminal 168 and the lower electrode terminal 170 are formed to beconnected with the piezoelectric layer 160 electrically.

[0222]FIG. 28 shows further other embodiment of the ink cartridge of thepresent invention. FIG. 28(A) is a cross sectional view of the bottompart of the ink cartridge of the present embodiment. The ink cartridgeof the present embodiment has a through hole 1 c on the bottom face 1 aof the container 1, which contains ink. The bottom part of the throughhole 1 c is closed by the actuator 650 and forms an ink storing part.

[0223]FIG. 28(B) shows a detailed cross section of the actuator 650 andthe through hole 1 c shown in FIG. 28(A). FIG. 28(C) shows a plan viewof the actuator 650 and the through hole 1 c shown in FIG. 28(B). Theactuator 650 has a vibrating plate 72 and a piezoelectric element 73which is fixed to the vibrating plate 72. The actuator 650 is fixed tothe bottom face of the container 1 such that the piezoelectric element73 can face to the through hole 1 c through the vibrating plate 72 andthe base plate 72. The vibrating plate 72 can be elastically deformedand is ink resistant.

[0224] Amplitude and frequency of the counter electromotive forcegenerated by the residual vibration of the piezoelectric element 73 andthe vibrating plate 72 changes with the ink quantity in the container 1.The through hole 1 c is formed on the position which is faced toactuator 650, and the minimum constant amount of ink is secured in thethrough hole 1 c. Therefore, the status of the end of ink end can bereliably detected by previously measuring the characteristic of thevibration of the actuator 650, which is determined by the ink quantitysecured in the through hole 1 c.

[0225]FIG. 29 shows other embodiment of the through hole 1 c. In each ofFIGS. 29(A), (B), and (C), the left hand side of the figure shows thestatus that there is no ink K in the through hole 1 c, and the righthand side of the figure shows the status that ink K is remained in thethrough hole 1 c. In the embodiment of FIG. 28, the side face of thethrough hole 1 c is formed as the vertical wall. In FIG. 29(A), the sideface 1 d of the through hole 1 c is slanted in vertical direction andopens with expanding to the outside. In FIG. 29(B), a stepped portion 1e and 1 f are formed on the side face of the through hole 1 c. Thestepped portion 1 f, which is provided above the stepped portion 1 e, iswider than the stepped portion 1 e. In FIG. 29(C), the through hole 1 chas a groove 1 g that extends to the direction in which ink is easilydischarged, that is, the direction to a ink supply port 2.

[0226] According to the shape of the through hole 1 c shown in FIGS.29(A) to (C), the quantity of ink K in the ink storing part can bereduced. Therefore, because the M′cav can be smaller than the M′maxexplained in FIG. 20 and FIG. 21, the vibration characteristic of theactuator 650 at the time of the ink end status can be greatly differentwith the vibration characteristic when enough quantity of ink K forprinting is remained in the container 1, and thus the ink end status canbe reliably detected.

[0227]FIG. 30 shows a slant view of the other embodiment of theactuator. The actuator 660 has packing 76 on the outside of the baseplate, which constitutes the actuator 660, or the through hole 1 c of amounting plate 72. Caulking holes 77 are formed on the outskirts of theactuator 660. The actuator 660 is fixed to the container 1 through thecaulking hole 77 with caulking. FIGS. 31(A) and (B) is a slant view ofthe further other embodiment of the actuator. In this embodiment, theactuator 670 comprises a concave part forming base plate 80 and apiezoelectric element 82. The concave part 81 is formed on the one sideof the face of the concave part forming base plate 80 by the techniquesuch as etching, and piezoelectric element 82 is mounted on the otherside of the face of the concave part forming base plate 80. The bottomportion of the concave part 81 operates as a vibrating region within theconcave part forming base plate 80. Therefore, the vibrating region ofthe actuator 670 is determined by the periphery of the concave part 81.Furthermore, the actuator 670 has the similar structure with thestructure of the actuator 106 shown in FIG. 20, in which the base plate178 and the vibrating plate 176 is formed as one body. Therefore, themanufacturing process during the manufacturing an ink cartridge can bereduced, and the cost for manufacturing an ink cartridge also can bereduced. The actuator 670 has a size which can be embedded into thethrough hole 1 c provided on the container 1. By this embedding process,the concave part 81 can operates as the cavity. The actuator 106 shownin FIG. 20 can be formed to be embedded into through hole 1 c asactuator 670 shown in FIG. 31.

[0228]FIG. 32 shows a slant view of the configuration that forms theactuator 106 in one body as a mounting module 100. The module 100 ismounted on the predetermined position of the container 1 of an inkcartridge. The module 100 is constituted to detect the ink consumptionstatus in the container 1 by detecting at least the change of acousticimpedance of the ink liquid. The module 100 of the present embodimenthas a liquid container mounting member 101 for mounting the actuator 106to the container 1. The liquid container mounting member 101 has astructure which mounts a cylindrical part 116 that contains the actuator106 which oscillates by the driving signal on a base mount 102, the planof which is substantially rectangular. Because the module 100 isconstructed so that the actuator 106 of the module 100 can not becontact from outside when the module 100 is mounted on the inkcartridge, the actuator 106 can be protected from outside contact. Thetop side of the edge of the cylindrical part 116 is chamfered so thatthe cylindrical part 116 can be easily fit into the hole which is formedin the ink cartridge.

[0229]FIG. 33 shows an exploded view of the module 100 shown in FIG. 32to show the structure of the module 100. The module 100 includes aliquid container mounting member 101 made from a resin and apiezoelectric device mounting member 105 which has a plate 110 and aconcave part 113. Furthermore, the module 100 has a leadwire 104 a and104 b, actuator 106, and a film 108. Preferably, the plate 110 is madefrom a material which is difficult to be rust such as stainless orstainless alloy. The opening 114 is formed on the central part of thecylindrical part 116 and the base mount 102 which are included in theliquid container mounting member 101 so that the cylindrical part 116and the base mount 102 can contain the lead wire 104 a and 104 b. Theconcave part 113 is formed on the central part of the cylindrical part116 and the base mount 102 so that the cylindrical part 116 and the basemount 102 can contain the actuator 106, the film 108, and the plate 110.The actuator 106 is connected to the plate 110 through the film 108, andthe plate 110 and the actuator 106 are fixed to the liquid containermounting member 101. Therefore, the lead wire 104 a and 104 b, theactuator 106, the film 108 and the plate 110 are mounted on the liquidcontainer mounting member 101 as one body. Each of the lead wire 104 aand 104 b transfer a driving signal to piezoelectric layer by couplingwith the upper electrode and the lower, electrode 166 of the actuator106, and also transfer the signal of resonant frequency detected by theactuator 106 to recording apparatus. The actuator 106 oscillatestemporally based on the driving signal transferred from the lead wire104 a and 104 b. The actuator 106 vibrates residually after theoscillation and generates a counter electromotive force by the residualvibration. By detecting the vibrating period of the waveform of thecounter electromotive force, the resonant frequency corresponding to theconsumption status of the liquid in the liquid container can bedetected. The film 108 bonds the actuator 106 and the plate 110 to sealthe actuator 106. The film 108 is preferably formed by such aspolyolefin and bonded to the actuator 106 and the plate 110 by heatsealing. By bonding the actuator 106 and the plate 110 with the film 108face with face, the unevenness of the bonding on location decreases, andthus the portion other than the vibrating plate does not vibrate.Therefore, the change of the resonant frequency before and after bondingthe actuator 106 to plate 110 is small.

[0230] The plate 110 is circular shape, and the opening 114 of the basemount 102 is formed in cylindrical shape. The actuator 106 and the film108 are formed in rectangular shape. The lead wire 104, the actuator106, the film 108, and the plate 110 can be attached to and removed fromthe base mount 102. Each of the base mount 102, the lead wire 104, theactuator 106, the film 108, and the plate 110 is arranged symmetric withrespect to the central axis of the module 100. Furthermore, each of thecenters of the base mount 102, the actuator 106, the film 108, and theplate 110 is arranged substantially on the central axis of the module100.

[0231] The opening 114 of the base mount 102 is formed such that thearea of the opening 114 is larger than the area of the vibrating regionof the actuator 106. The through hole 112 is formed on the center of theplate 110 where the vibrating section of the actuator 106 faces. Asshown in FIG. 20 and FIG. 21, the cavity 162 is formed on the actuator106, and both of the through hole 112 and the cavity 162 forms inkstoring part. The thickness of the plate 110 is preferably smaller thandiameter of the through hole 112 to reduce the influence of the residualink. For example, the depth of the through hole 112 is preferablysmaller than one third of the diameter of the through hole 112. Theshape of the through hole 112 is substantially true circle and symmetricwith respect to the central axis of the module 100. Furthermore, thearea of the through hole 112 is larger than the area of opening of thecavity 162 of the actuator 106. The periphery of the shape of thecross-section of the through hole 112 can be tapered shape of steppedshape. The module 100 is mounted on the side, top, or bottom of thecontainer 1 such that the through hole 112 faces to the inside of thecontainer 1. When the ink is consumed, and the ink around the actuator106 is exhausted, the resonant frequency of the actuator 106 greatlychanges. The change of the ink level can thus be detected.

[0232]FIG. 34 shows the slant view of the other embodiments of themodule. The piezoelectric device mounting member 405 is formed on theliquid container mounting member 101 in the module 400 of the presentembodiment. The cylindrical part 403, which has a cylindrical shape, isformed on the base mount 102, which has a square shaped plan, the edgesof which are rounded, in the liquid container mounting member 401.Furthermore, the piezoelectric apparatus mounting member 405 includes aboard shaped element 405, which is set up on the cylindrical part 403,and a concave part 413. The actuator 106 is arranged on the concave part413 provided on the side face of the board shaped element 406. The topend of the board shaped element 406 is chamfered in predetermined angleso that the board shaped element is easy to fit into hole formed on theink cartridge when mounting the actuator 106 to ink cartridge.

[0233]FIG. 35 shows an exploded view of the module 400 shown in FIG. 34to show the structure of the module 400. As the module 100 shown in FIG.32, the module 400 includes a liquid container mounting member 401 and apiezoelectric device mounting member 405. The liquid container mountingmember 401 has the base mount 402 and the cylindrical part 403, and thepiezoelectric device mounting member 405 has the board shaped element406 and the concave part 413. The actuator 106 is connected to the plate410 and fixed to the concave part 413. The module 400 has a lead wire404 a and 404 b, actuator 106, and a film 408.

[0234] According to the present embodiment, the plate 410 is rectangularshape, and the opening 414 provided on the board shaped element 406 isformed in rectangular shape. The lead wire 404 a and 404 b, the actuator106, the film 408, and the plate 410 can be attached to and removed fromthe base mount 402. Each of the actuator 106, the film 408, and theplate 410 is arranged symmetric with respect to the central axis whichis extended to perpendicular direction to the plan of opening 414 andalso pass through the center of opening 414. Furthermore, each of thecenters of the actuator 106, the film 408, and the plate 410 is arrangedsubstantially on the central axis of the opening 414.

[0235] The through hole 412 provided on the center of the plate 410 isformed such that the area of the through hole 412 is larger than thearea of the opening of the cavity 162 of the actuator 106. The cavity162 of the actuator 106 and the through hole 412 together forms inkstoring part. The thickness of the plate 410 is preferably smaller thandiameter of the through hole 412. For example, the thickness of theplate 410 is smaller than one third of the diameter of the through hole412. The shape of the through hole 412 is substantially true circle andsymmetric with respect to the central axis of the module 400. The shapeof the cross-section of the periphery of the through hole 112 can betapered shape or stepped shape. The module 400 can be mounted on thebottom of the container 1 such that the through hole 412 is arrangedinside of the container 1. Because the actuator 106 is arranged insidethe container 1 such that the actuator 106 extends in the verticaldirection, the setting of the timing of the ink end can be easilychanged by changing the height of the mounting position of the actuator106 in the container 1 by changing the height of the base mount 402.

[0236]FIG. 36 shows the further other embodiment of the module. As themodule 100 shown in FIG. 32, the module 500 of FIG. 36 includes a liquidcontainer mounting member 501 which has a base mount 502 and acylindrical part 503. Furthermore, the module 500 further has a leadwire 504 a and 504 b, actuator 106, a film 508, and a plate 510. Theopening 514 is formed on the center of the base mount 502, which isincluded in the liquid container mounting member 501, so that the basemount 502 can contain the lead wire 504 a and 504 b. The concave part513 is formed on the cylindrical part 503 so that the cylindrical part503 can contain the actuator 106, the film 508, and the plate 510. Theactuator 106 is fixed to the piezoelectric device mounting member 505through the plate 510. Therefore, the lead wire 504 a and 504 b, theactuator 106, the film 508, and the plate 510 are mounted on the liquidcontainer mounting member 501 as one body. The cylindrical part 503, thetop face of which is slanted in vertical direction, is formed on thebase mount which has a square shaped plan and the edges of which arerounded. The actuator 106 is arranged on the concave part 513 which isprovided on the top surface of the cylindrical part 503 that is slantedin vertical direction.

[0237] The top end of the module 500 is slanted, and the actuator 106 ismounted on this slanted surface. Therefore, if the module 500 is mountedon the bottom or the side of the container 1, the actuator 106 slants inthe vertical direction of the container 1. The slanting angle of the topend of the module 500 is substantially between 30 degree and 60 degreewith considering the detecting performance.

[0238] The module 500 is mounted on the bottom or the side of thecontainer 1 so that the actuator 106 can be arranged inside thecontainer 1. When the module 500 is mounted on the side of the container1, the actuator 106 is mounted on the container 1 such that the actuator106 faces the upside, downside, or side of the container 1 withslanting. When the module 500 is mounted on the bottom of the container1, the actuator 106 is preferable to be mounted on the container 1 suchthat the actuator 106 faces to the ink supply port side of the container1 with slanting.

[0239]FIG. 37 shows a cross-sectional view around the bottom of thecontainer 1 when the module 100 shown in FIG. 32 is mounted on thecontainer 1. The module 100 is mounted on the container 1 so that themodule 100 penetrates through the side wall of the container 1. TheO-ring 365 is provided on the connection face of between the side wallof the container 1 and the module 100 to seal between the module 100 andthe container 1. The module 100 is preferable to include the cylindricalpart as explained in FIG. 32 so that the module 100 can be sealed by theO-ring. By inserting the top end of the module 100 inside the container1, ink in the container 1 contacts with the actuator 106 through thethrough hole 112 of the plate 110. Because the resonant frequency of theresidual vibration of the actuator 106 is different depends on whetherthe circumference of the vibrating section of the actuator 106 is liquidor gas, the ink consumption status can be detected using the module 100.Furthermore, not only the module 100 can be mounted on the container 1and detect the existence of ink, but also the module 400 shown in FIG.34, module 500 shown in FIG. 36, or the module 700A and 700B shown inFIG. 38, and a mold structure 600 can be mounted on the container 1 anddetect the existence of the ink.

[0240]FIG. 38(A) shows the cross section of the ink container whenmounting module 700B on the container 1. The present embodiment uses amodule 700B as an example of a mounting structure.

[0241] The actuator 106 includes the piezoelectric layer 160, the upperelectrode 164, the lower electrode 166, the vibrating plate 176, and themounting plate 350. The vibrating plate 176 is formed on the mountingplate 350, and the lower electrode 166 is formed on the vibrating plate176. The piezoelectric layer 160 is formed on the top face of the lowerelectrode 166, and the upper electrode 164 is formed on the top face ofthe piezoelectric layer 160. Therefore, the main portion of thepiezoelectric layer 160 is formed by sandwiching the main portion of thepiezoelectric layer 160 by the main portion of the upper electrode 164and the lower electrode 166 from top and bottom. The circular portion,which is a main portion of each of the piezoelectric layer 160, theupper electrode 164, and the lower electrode 166, forms a piezoelectricelement. The piezoelectric element is formed on the vibrating plate 176.The vibrating region of the piezoelectric element and the vibratingplate 176 constitutes the vibrating section, on which the actuator 106actuary vibrates.

[0242] The module 700B is mounted on the container 1 such that theliquid container mounting member 360 protrude into the inside of the Athrough hole 370 is formed in the mounting plate 350, and the throughhole 370 faces to the vibrating section of the actuator 106.Furthermore, a hole 382 is formed on the bottom wall of the module 700B,and a piezoelectric device mounting member 363 is formed. The actuator106 is arranged to close the one of the face of the hole 382. Therefore,ink contacts with the vibrating plate 176 through the hole 382 of thepiezoelectric device mounting member 363 and the through hole 370 of themounting plate 350. The hole 382 of the piezoelectric device mountingmember 363 and the through hole 370 of the mounting plate 350 togetherforms an ink storing part. The piezoelectric device mounting member 363and the actuator 106 are fixed by the mounting plate 350 and the filmmaterial. The sealing structure 372 is provided on the connection partof the liquid container mounting member 360 and the container 1. Thesealing structure 372 can be formed by the plastic material such assynthetic resin or O-ring. In FIG. 38(A), the module 700B and thecontainer 1 is separate body, however, the piezoelectric device mountingmember can be constituted by a part of the container 1 as shown in FIG.38(B).

[0243] There is possibility that the actuator 106 malfunctions by thecontact of the ink which is dropped from a top face or a side face ofthe container 1 with the actuator 106, the ink of which is attached tothe top face or the side face of the container 1 when the ink cartridgeis shaken. However, because the liquid container mounting member 360 ofthe module 700B protrudes into the inside of the container 1, theactuator 106 does not malfunction by the ink dropped from the top faceor the side face of the container 1.

[0244]FIG. 38(B) shows the cross section of the ink container whenmounting actuator 106 on the container 1. A protecting member 361 ismounted on the container 1 separately with the actuator 106 in the inkcartridge of the embodiment shown in FIG. 38(B). Therefore, theprotecting member 361 and the actuator 106 is not one body as a module,and the protecting member 361 thus can protect the actuator 106 not tobe contact by the user. A hole 380 which is provide on the front face ofthe actuator 106 is arranged on the side wall of the container 1. Athrough hole 370 is provided on the mounting plate 350. Furthermore, ahole 380 is formed on the side wall of the container 1. Therefore, inkcontacts with the vibrating plate 176 through the hole 380 of thecontainer 1 and the through hole 370 of the mounting plate 350. The hole380 of the container land the through hole 370 of the mounting plate 350together forms ink storing part. Moreover, because the actuator 106 isprotected by the protecting member 361, the actuator 106 can beprotected form the outside contact. The base plate 178 shown in FIG. 20can be used instead of the mounting plate 350 in the embodiment shown inFIGS. 38(A) and (B).

[0245]FIG. 38(C) shows an embodiment that comprises a mold structure 600which includes the actuator 106. In the present embodiment, a moldstructure 600 is used as one example of the mounting structure. The moldstructure 600 has the actuator 106 and a mold member 364. The actuator106 and the mold member 364 are formed in one body. The mold member 364is formed by a plastic material such as silicon resin. The mold member364 includes a lead wire 362 in its inside. The mold member 364 isformed so that the mold member 364 has two legs extended from theactuator 106. The end of the two legs of the mold member 364 are formedin a shape of hemisphere to liquid tightly fix the mold member 364 withcontainer 1. The mold member 364 is mounted on the container 1 such thatthe actuator 106 protrudes into the inside of the container 1, and thevibrating section of the actuator 106 contacts with ink inside thecontainer 1. The upper electrode 164, the piezoelectric layer 160, andthe lower electrode 166 of the actuator 106 are protected from ink bythe mold member 364.

[0246] Because the mold structure 600 shown in FIG. 38 does not need thesealing structure 372 between the mold member 364 and the container 1,the leaking of ink from the container 1 can be reduced. Moreover,because the mold structure 600 has a form that the mold structure 600does not protrude from the outside of the container 1, the moldstructure 600 can protect the actuator 106 from the outside contact.There is possibility that the actuator 106 malfunctions by the contactof the ink which is dropped from a top face or a side face of thecontainer 1 with the actuator 106, the ink of which is attached to thetop face or the side face of the container 1 when the ink cartridge isshaken. Because the mold member 364 of the mold structure 600 protrudesinto the inside of the container 1, the actuator 106 does notmalfunction by the ink dropped from the top face or the side face of thecontainer 1.

[0247]FIG. 39 shows an embodiment of an ink cartridge and an ink jetrecording apparatus which uses the actuator 106 shown in FIG. 20. Aplurality of ink cartridges 180 is mounted on the ink jet recordingapparatus which has a plurality of ink introducing members 182 and aholder 184 each corresponding to the each of ink cartridge 180,respectively. Each of the plurality of ink cartridges 180 containsdifferent types of ink, for example, different color of ink. Theactuator 106, which detects at least acoustic impedance, is mounted onthe each of bottom of the plurality of ink cartridge 180. The residualquantity of ink in the ink cartridge 180 can be detected by mounting theactuator 106 on the ink cartridge 180.

[0248]FIG. 40 shows a detail around the head member of the ink jetrecording apparatus. The ink jet recording apparatus has an inkintroducing member 182, a holder 184, a head plate 186, and a nozzleplate 188. A plurality of nozzle 190, which jet out ink, is formed onthe nozzle plate 188. The ink introducing member 182 has an air supplyhole 181 and an ink introducing inlet 183. The air supply hole 181supplies air to the ink cartridge 180. The ink introducing inlet 183introduces ink from the ink cartridge 180. The ink cartridge 180 has anair introducing inlet 185 and an ink supply port 187. The airintroducing inlet 185 introduces air from the air supply hole 181 of theink introducing member 182. The ink supply port 187 supplies ink to theink introducing inlet 183 of the ink introducing member 182. Byintroducing air from the ink introducing member 182 to the ink cartridge180, the ink cartridge 180 accelerates the supply of ink from the inkcartridge 180 to the ink introducing member 182. The holder 184communicates ink supplied from the ink cartridge 180 through the inkintroducing member 182 to the head plate 186.

[0249]FIG. 41 shows other embodiment of the ink cartridge 180 shown inFIG. 40. The actuator 106 is mounted on the bottom face 194 a, which isformed to be slanted in vertical direction, of the ink cartridge 180Ashown in the FIG. 41(A). A wave preventing wall 192 is provided on theposition where has the predetermined height from the bottom face of theinside the ink container 194 and also faces to the actuator 106 insidethe ink container 194 of the ink cartridge 180. Because the actuator 106is mounted on the ink container 194 slanted in vertical direction, thedrainage of ink can be improved.

[0250] A gap, which is filled with ink, is formed between the actuator106 and the wave preventing wall 192. The space between the wavepreventing wall 192 and the actuator 106 has a space such that the spacedoes not hold ink by capillary force. When the ink container 194 isrolled, ink wave is generated inside the ink container 194 by therolling, and there is possibility that the actuator 106 malfunctions bydetecting gas or an air bubble caused by the shock of the ink wave. Byproviding the wave preventing wall 192, ink wave around the actuator 106can be prevented so that the malfunction of the actuator 106 can beprevented.

[0251] The actuator 106 of the ink cartridge 180B shown in FIG. 41 ismounted on the side wall of the supply port of the ink container 194.The actuator 106 can be mounted on the side wall or bottom face of theink container 194 if the actuator 106 is mounted nearby the ink supplyport 187. The actuator 106 is preferably mounted on the center of thewidth direction of the ink container 194. Because ink is supplied to theoutside through the ink supply port 187, ink and actuator 106 reliablycontacts until the timing of the ink near end by providing the actuator106 nearby the ink supply port 187. Therefore, the actuator 106 canreliably detect the timing of the ink near end.

[0252] Furthermore, by providing the actuator 106 nearby the ink supplyport 187, the setting position of the actuator 106 to the connectionpoint on the carriage on the ink container becomes reliable during themounting of the ink container on the cartridge holder of the carriage.It is because the reliability of coupling between the ink supply portwith the ink supply needle is most important during the coupling of theink container and the carriage. If there is even a small gap, the tip ofthe ink supply needle will be hurt or a sealing structure such as O-ringwill be damaged so that the ink will be leaked. To prevent this kind ofproblems, the ink jet printer usually has a special structure that canaccurately positioning the ink container during the mounting of the inkcontainer on the carriage. Therefore, the positioning of the actuator106 becomes reliable by arranging the actuator nearby the ink supplyport. Furthermore, the actuator 106 can be further reliably positionedby mounting the actuator 106 at the center of the width direction of theink container 194. It is because the rolling is the smallest when theink container rolls along an axis, the center of which is center line ofthe width direction, during the mounting of the ink container on theholder.

[0253]FIG. 42 shows further other embodiment of the ink cartridge 180.FIG. 42(A) shows a cross section of an ink cartridge 180C, and FIG.42(B) shows a cross section which enlarges the side wall 194 b of an inkcartridge 180C shown in FIG. 42(A). FIG. 42(C) shows perspective viewfrom the front of the side wall 194 b of the ink cartridge 180C. Thesemiconductor memory device 7 and the actuator 106 are formed on thesame circuit board 610 in the ink cartridge 180C. As shown in FIGS.42(B) and (C), the semiconductor memory device 7 is formed on the upperside of the circuit board 610, and the actuator 106 is formed on thelower side of the semiconductor memory device 7 on the same circuitboard 610. A different-type O-ring 614 is mounted on the side wall 194 bsuch that the different-type O-ring 614 surrounds the actuator 106. Aplurality of caulking part 616 is formed on the side wall 194 b tocouple the circuit board 610 with the ink container 194. By coupling thecircuit board 610 with the ink container 194 using the caulking part 616and pushing the different-type O-ring 614 to the circuit board 610, thevibrating region of the actuator 106 can contacts with ink, and at thesame time, the inside of the ink cartridge is sealed from outside of theink cartridge.

[0254] A terminals 612 are formed on the semiconductor memory device 7and around the semiconductor memory device 7. The terminal 612 transferthe signal between the semiconductor memory device 7 and outside the inkjet recording apparatus. The semiconductor memory device 7 can beconstituted by the semiconductor memory which can be rewritten such asEEPROM. Because the semiconductor memory device 7 and the actuator 106are formed on the same circuit board 610, the mounting process can befinished at one time during mounting the semiconductor memory device 7and the actuator 106 on the ink cartridge 180C. Moreover, the workingprocess during the manufacturing of the ink cartridge 180C and therecycling of the ink cartridge 180C can be simplified. Furthermore, themanufacturing cost of the ink cartridge 180C can be reduced because thenumbers of the parts can be reduced.

[0255] The actuator 106 detects the ink consumption status inside theink container 194. The semiconductor memory device 7 stores theinformation of ink such as residual quantity of ink detected by theactuator 106. That is, the semiconductor memory device 7 stores theinformation related to the characteristic parameter such as thecharacteristic of ink and the ink cartridge used for the actuator 106when detecting the ink consumption status. The semiconductor memorydevice 7 previously stores the resonant frequency of when ink inside theink container 194 is full, that is, when ink is filled in the inkcontainer 194 sufficiently, or when ink in the ink container 194 is end,that is, ink in the ink container 194 is consumed, as one of thecharacteristic parameter. The resonant frequency when the ink inside theink container 194 is full status or end status can be stored when theink container is mounted on the ink jet recording apparatus for thefirst time. Moreover, the resonant frequency when the ink inside the inkcontainer 194 is full status or end status can be stored during themanufacturing of the ink container 194. Because the unevenness of thedetection of the residual quantity of ink can be compensated by storingthe resonant frequency when the ink inside the ink container 194 is fullstatus or end status in the semiconductor memory device 7 previously andreading out the data of the resonant frequency at the ink jet recordingapparatus side, it can be accurately detected that the residual quantityof ink is decreased to the reference value.

[0256]FIG. 43 shows further other embodiment of the ink cartridge 180. Aplurality of actuators 106 is mounted on the side wall 194 b of the inkcontainer 194 in the ink cartridge 180D shown in FIG. 43(A). It ispreferable to use the plurality of the actuators 106 which is formed inone body as shown in FIG. 24 for these plurality of actuators 106. Theplurality of actuators 106 is arranged on the side wall 194 b withinterval in vertical direction. By arranging the plurality of actuators106 on the side wall 194 b with interval in vertical direction, theresidual quantity of ink can be detected step by step.

[0257] The ink cartridge 180E shown in FIG. 43(B) mounts a actuator 606which is long in vertical direction on the side wall 194 b of the inkcontainer 194. The change of the residual quantity of ink inside the inkcontainer 194 can be detected continuously by the actuator 606 which islong in vertical direction. The length of the actuator 606 is preferablylonger than the half of the height of the side wall 194 b. In FIG.43(B), the actuator 606 has the length from the substantially from thetop end to the bottom end of the sidewall 194 b.

[0258] The ink cartridge 180F shown in FIG. 43(C) mounts a plurality ofactuators 106 on the side wall 194 b of the ink container 194 as the inkcartridge 180D shown in FIG. 43(A). The ink cartridge 180F furthercomprises the wave preventing wall 192, which is long in verticaldirection, along the side wall 194 b with predetermined space with theside wall 194 b such that the wave preventing wall 192 faces directly tothe plurality of actuators 106. It is preferable to use the plurality ofthe actuators 106 which is formed in one body as shown in FIG. 24 forthese plurality of actuators 106. A gap which is filled with ink isformed between the actuator 106 and the wave preventing wall 192.Moreover, the gap between the wave preventing wall 192 and the actuator106 has a space such that the gap does not hold ink by capillary force.When the ink container 194 is rolled, ink wave is generated inside theink container 194 by the rolling, and there is possibility that theactuator 106 malfunctions by detecting gas or an air bubble caused bythe shock of the ink wave. By providing the wave preventing wall 192,ink wave around the actuator 106 can be prevented so that themalfunction of the actuator 106 can be prevented. The wave preventingwall 192 also prevents the air bubble generated by the rolling of ink toenter to the actuator 106.

[0259]FIG. 45 shows further other embodiment of the ink cartridge 180.The ink cartridge 180G shown in FIG. 45(A) has a plurality of partitionwalls 212, each of which extends downward from the top face 194 c of theink container 194. Because each of lower end of the partition walls 212and the bottom face of the ink container 194 has a predetermined gap,the bottom part of the ink container 194 communicates with each other.The ink cartridge 180G has a plurality of containing chambers 213divided by the each of plurality of partition walls 212. The bottom partof the plurality of the containing chambers 213 communicates with eachother. In each of the plurality of the containing chamber 213, theactuator 106 is mounted on the top face 194 c of the ink container 194.It is preferable to use the plurality of the actuators 106 which isformed in one body as shown in FIG. 24 for these plurality of actuators106. The actuator 106 is arranged on substantially center of the topface 194 c of the containing chamber 213 of the ink container 194. Thevolume of the containing chamber 213 is arranged such that the volume ofthe containing chamber 213 of the ink supply port 187 is the largest,and the volume of the containing chamber 213 gradually decreases as thedistance from the ink supply port 187 increases to the inner part of theink cartridge 180G.

[0260] Therefore, the space between each of the actuator 106 is widestat the ink supply port 187 side and becomes narrower as the distancefrom the ink supply port 187 increases to the inner part of the inkcartridge 180G. Because ink is drained from the ink supply port 187, andair enters from the air introducing inlet 185, ink is consumed from thecontaining chamber 213 of the ink supply port 187 side to the containingchamber 213 of the inner part of the ink cartridge 180G. For example,the ink in the containing chamber 213 which is most near to the inksupply port 187 is consumed, and during the ink level of the containingchamber 213 which is most near to the ink supply port 187 decreases, theother containing chamber 213 are filled with ink. When the ink in thecontaining chamber 213 which is most near to the ink supply port 187 isconsumed totally, air enters to the containing chamber 213 which issecond by counted from the ink supply port 187, then the ink in thesecond containing chamber 213 is beginning to be consumed so that theink level of the second containing chamber 213 begin to decrease. Atthis time, ink is filled in the containing chamber 213 which is third ormore than third by counted from the ink supply port 187. In this way,ink is consumed from the containing chamber 213 which is most near tothe ink supply port 187 to the containing chamber 213 which is far fromthe ink supply port 187 in order.

[0261] As shown above, because the actuator 106 is arranged on the topface 194 c of the ink container 194 with interval for each of thecontaining chamber 213, the actuator 106 can detect the decrease of theink quantity step by step. Furthermore, because the volume of thecontaining chamber 213 decreases from the ink supply port 187 to theinner part of the containing chamber 213 gradually, the time intervalwhen the actuator 106 detects the decrease of the ink quantity graduallydecreases. Therefore, the frequency of the ink quantity detection can beincreased as the ink end is drawing near.

[0262] The ink cartridge 180H shown in FIG. 44(B) has one partition wall212 which extends downward from the top face 194 c of the ink container194. Because lower end of the partition walls 212 and the bottom face ofthe ink container 194 have a predetermined space, the bottom part of theink container 194 communicates with each other. The ink cartridge 180Hhas two containing chambers 213 a and 213 b divided by the partitionwall 212. The bottom part of the containing chambers 213 a and 213 bcommunicates with each other. The volume of the containing chamber 213 aof the ink supply port 187 side is larger than the volume of thecontaining chamber 213 b which is located in a inner part of the inkcartridge 180H far from the ink supply port 187. The volume of thecontaining chamber 213 b is preferably smaller than the half of thevolume of the containing chamber 213 a.

[0263] The actuator 106 is mounted on the top face 194 c of thecontaining chamber 213B. Furthermore, a buffer 214, that is a groove forcatching the air bubble which enters to the ink cartridge 180H duringmanufacturing of the ink cartridge 180H, is formed on the containingchamber 213 b. In FIG. 44(B), the buffer 214 is formed as a grooveextended upward from the side wall 194 b of the ink container 194.Because the buffer 214 catches the air bubble enters inside thecontaining chamber 213 b, the malfunction of the actuator 106 bydetecting an ink end when catching the air bubble can be prevented.Furthermore, by providing actuator 106 on the top face 194 c of thecontaining chamber 213 b, ink can be completely consumed by compensatingthe ink quantity, which is measured from the detection of the ink enduntil the complete consumption of ink, with the corresponding inkconsumption status of the containing chamber 213 a calculated from thedot counter. Furthermore, by adjusting the volume of the containingchamber 213 b by changing the length or the interval of the partitionwall 212, the ink quantity which can be consumed after the detection ofthe ink end can be changed.

[0264] The ink cartridge 180I shown in FIG. 44(C) fills a porous member216 in the containing chamber 213 b of the ink cartridge 180H shown inFIG. 44(B). The porous member 216 is filled inside the containingchamber 213 b from the top face to the bottom face of the porous member216 b. The porous member 216 contacts with the actuator 106. There is apossibility that the actuator 106 malfunctions by the entering of theair bubble inside the containing chamber 213 b when the ink containerfall down or when the containing chamber 213 b moves back and forth withthe carriage. If the porous member 216 is provided on the containingchamber 213 b, the porous member 216 captures air to prevent entering ofair into the actuator 106. Furthermore, because the porous member 216holds ink, the porous member 216 can prevent the actuator 106 tomalfunction as detecting the ink end status as ink exist status which iscaused by attaching of the ink on the actuator 106 when the inkcontainer shakes. The porous member 216 is preferable to be provided inthe containing chamber 213 having a smallest volume. Furthermore, byproviding actuator 106 on the top face 194 c of the containing chamber213 b, ink can be consumed to the end by compensating the ink quantitywhich is measured from the detection of the ink end until the completeconsumption of ink. Furthermore, The ink quantity which can be consumedafter the detection of the ink near end can be changed by adjusting thevolume of the containing chamber 213 b by changing the length andinterval of the partition wall 212.

[0265]FIG. 44(D) shows an ink cartridge 180J, the porous member 216 ofwhich is constituted by two kinds of porous members 216A and 216B havinga different hole diameter with each other. The porous member 216A islocated on the upper side of the porous member 216B. The hole diameterof the porous member 216A which is located on the upper side of thecontaining chamber 213 b is larger than the hole diameter of the porousmember 216B which is located on the lower side of the containing chamber213B. The porous member 216A can be formed by the member which has alower affinity for liquid than the affinity for liquid of the memberwhich forms the porous member 216B. Because the capillary force of theporous member 216B, which has small hole diameter, is larger than thecapillary force of the porous member 216A, which has large holediameter, the ink in the containing chamber 213 b is collected to theporous member 216B located on the lower side of the containing chamber213B and held by the porous member 216B. Therefore, once the air reachesto the actuator 106, and the actuator 106 detects the non-ink status,ink does not reaches to the actuator 106 again so that the actuator 106does not malfunction to detect the ink exist status. Furthermore,because the porous member 216B which is far from the actuator 106absorbs ink, the drainage of ink around the actuator 106 improves, andthe quantity of change of the acoustic impedance during the detection ofthe ink existence increases. Moreover, by providing the actuator 106 onthe top face 194 c of the containing chamber 213 b, ink can be consumedto the end by compensating the ink quantity which is measured from thedetection of the ink near end until the complete consumption of ink.Furthermore, The ink quantity which can be consumed after the detectionof the ink near end can be changed by adjusting the volume of thecontaining chamber 213 b by changing the length and interval of thepartition wall 212.

[0266]FIG. 45 shows a cross section of an ink cartridge 180K which isfurther other embodiment of the ink cartridge 180I shown in FIG. 44(C).The porous member 216 in the ink cartridge 180K shown in FIG. 45 isdesigned such that the area of the cross section on the horizontal planeof the lower part of the porous member 216 is compressed to be decreasesgradually to the direction to the bottom face of the ink container 194.Therefore, the hole diameter of the porous member 216 decreasesgradually to the direction to the bottom face of the ink container 194.Ink cartridge 180K shown in FIG. 45(A) has a rib which is provided onthe side wall of the ink container 194 to compress the lower part of theporous member 216 to reduce the hole diameter of the lower part of theporous member 216. Because the hole diameter of the lower part of theporous member 216 reduced by the compression, ink is collected and heldby the lower part of the porous member 216. Because the lower part ofthe porous member 216 which is far from the actuator 106 absorbs ink,the drainage of ink around the actuator 106 improves, and the quantityof change of the acoustic impedance during the detection of the inkexistence increases. Therefore, the error, of which the actuator 106detects the non ink status as the ink exist status by the attaching ofink on the actuator 106 mounted on the top face of the ink cartridge180K by rolling of ink, can be prevented

[0267] In the ink cartridge 180L shown in FIG. 45(B) and FIG. 45(C), tocompress to decrease the area of the cross section on the horizontalplane of the lower part of the porous member 216 gradually to thedirection to the bottom face of the ink container 194, the area of thecross section on the horizontal plane of the containing chambergradually decreases to the direction to the bottom face of the inkcontainer 194. Because the hole diameter of the lower part of the porousmember 216 reduced by the compression, ink is collected and held by thelower part of the porous member 216. Because the lower part of theporous member 216B which is far from the actuator 106 absorbs ink, thedrainage of ink around the actuator 106 improves, and the quantity ofchange of the acoustic impedance during the detection of the inkexistence increases. Therefore, the error, of which the actuator 106detects the non ink status as the ink exist status by the attaching ofink on the actuator 106 mounted on the top face of the ink cartridge180L by rolling of ink, can be prevented

[0268]FIG. 46 shows other embodiment of the ink cartridge using theactuator 106. The ink cartridge 220A shown in FIG. 46(A) has a firstpartition wall 222 provided such that it extends downward from the topface of the ink cartridge 220A. Because there is a predetermined spacebetween the lower end of the first partition wall 222 and the bottomface of the ink cartridge 220A, ink can flows into the ink supply port230 through the bottom face of the ink cartridge 220A. A secondpartition wall 224 is formed such that the second partition wall 224extends upward from the bottom face of the ink cartridge 220A on themore ink supply port 230 side of the first partition wall 222. Becausethere is a predetermined space between the upper end of the secondpartition wall 224 and the top face of the ink cartridge 220A, ink canflows into the ink supply port 230 through the top face of the inkcartridge 220A.

[0269] A first containing chamber 225 a is formed on the inner part ofthe first partition wall 222, seen from the ink supply port 230, by thefirst partition wall 222. On the other hand, a second containing chamber225 b is formed on the front side of the second partition wall 224, seenfrom the ink supply port 230, by the second partition wall 224. Thevolume of the first containing chamber 225 a is larger than the volumeof the second containing chamber 225 b. A capillary passage 227 isformed by providing a space, which can generate the capillaryphenomenon, between the first partition wall 222 and the secondpartition wall 224. Therefore, the ink in the first containing chamber225 a is collected to the capillary passage 227 by the capillary forceof the capillary passage 227. Therefore, the capillary passage 227 canprevent that the air or air bubble enters into the second containingchamber 225 b. Furthermore, the ink level in the second containingchamber 225 b can decrease steadily and gradually. Because the firstcontaining chamber 225 a is formed at more inner part of the secondcontaining chamber 225 b, seen from the ink supply port 230, the ink inthe second containing chamber 225 b is consumed after the ink in thefirst containing chamber 225 a is consumed.

[0270] The actuator 106 is mounted on the side wall of the ink cartridge220A of the ink supply port 230 side, that is, the side wall of thesecond containing chamber 225 b of the ink supply port 230 side. Theactuator 106 detects the ink consumption status inside the secondcontaining chamber 225 b. The residual quantity of ink at the timingclosed to the ink near end can be detected stably by mounting theactuator 106 on the side wall of the second containing chamber 225 b.Furthermore, by changing the height of the mounting position of theactuator 106 on the side wall of the second containing chamber 225 b,the timing to determine which ink residual quantity as an ink end can befreely set. Because ink is sullied from the first containing chamber 225a to the second containing chamber 225 b by the capillary passage 227,the actuator 106 does not influenced by the rolling of ink caused by therolling of the ink cartridge 220A, and actuator 106 can thus reliablymeasure the ink residual quantity. Furthermore, because the capillarypassage 227 holds ink, the capillary passage 227 can prevent ink to flowbackward from the second containing chamber 225 b to the firstcontaining chamber 225 a.

[0271] A check valve 228 is provided on the top face of the inkcartridge 220A. The leaking of ink outside of the ink cartridge 220Acaused by the rolling of the ink cartridge 220A can be prevented by thecheck valve 228. Furthermore, the evaporation of ink from the inkcartridge 220A can be prevented by providing the check valve 228 on thetop face of the ink cartridge 220A. If ink in the ink cartridge 220A isconsumed, and negative pressure inside the ink cartridge 220A exceedsthe pressure of the check valve 228, the check valve 228 opens andintroduces air into the ink cartridge 220A. Then the check valve 228closes to maintain the pressure inside the ink cartridge 220A to bestable.

[0272] FIGS. 46(C) and (D) shows a detailed cross-section of the checkvalve 228. The check valve 228 shown in FIG. 46(C) has a valve 232 whichincludes flange 232 a formed by rubber. An airhole 233, whichcommunicates air between inside and outside of the ink cartridge 220, isprovided on the ink cartridge 220 such that the airhole 233 faces to theflange 232 a. The airhole 233 is opened and closed by the flange 232 a.The check valve 228 opens the flange 232 a inward the ink cartridge 220when the negative pressure in the ink cartridge 220 exceeds the pressureof the check valve 228 by the decrease of ink inside the ink cartridge220A, and thus the air outside the ink cartridge 220 is introduced intothe ink cartridge 220. The check valve 228 shown in FIG. 46(D) has avalve 232 formed by rubber and a spring 235. If the negative pressureinside the ink cartridge 220 exceeds the pressure of the check valve228, the valve 232 presses and opens the spring 235 to introduce theoutside air into the ink cartridge 220 and then closes to maintain thenegative pressure inside the ink cartridge 220 to be stable.

[0273] The ink cartridge 220B shown in FIG. 46(B) has a porous member242 in the first containing chamber 225 a instead of providing the checkvalve 228 on the ink cartridge 220A as shown in FIG. 46. The porousmember 242 holds the ink inside the ink cartridge 220B and also preventsink to be leaked outside of the ink cartridge 220B during the rolling ofthe ink cartridge 220B.

[0274] The embodiment that the actuator 106 is mounted on an inkcartridge or a carriage, in which the ink cartridge is a separate bodywith the carriage and mounted on the carriage, has been explained above.However, the actuator 106 can be mounted on the ink tank which ismounted on the ink jet recording apparatus together with a carriage andformed together with a carriage as one body. Furthermore, the actuator106 can be mounted on the ink tank of the off-carriage type. Theoff-carriage type ink tank is a separate body with a carriage andsupplies ink to carriage through such as tube. Moreover, the actuator ofthe present embodiment can be mounted on the ink cartridge 180constituted so that a recording head and an ink container are formed ason body and possible to be exchanged. Liquid sensor and memory means(consumption data memory)

[0275] Description has been made concerning various ink cartridgeshaving ink consumption detecting capability according to the presentembodiments. These ink cartridges comprise the liquid sensor (actuatorand so on) and the memory means such as a semiconductor memory means. Asa result of features of the present embodiment, functions andadvantageous aspects realized by combinations of theses structuresthereof will be described below.

[0276] Referring to FIG. 47, an ink cartridge 800 corresponds to, forexample, the cartridge shown in FIG. 1. The ink cartridge 800 includes aliquid sensor 802 and a consumption data memory 804. The liquid sensor802 is comprised of the above described elastic wave generating means oractuator, and outputs a signal corresponding to the ink consumptionstate. The consumption data memeory is a mode of the memory means foruse with the liquid container according to the present invention. Theconsumption data memory 804 is a rewritable memory such as an EEPROM andcorresponds to the above described semiconductor memory means (FIG. 1,the reference numeral 7).

[0277] A recording device control unit 810 is comprised of a computerwhich controls the ink-jet recording apparatus. The recording devicecontrol unit 810 includes a consumption detecting process unit 812. Anink consumption detecting device comprises the consumption detectingprocess unit 812, the liquid sensor 802 and the consumption data memory804. The consumption detecting process unit 812 detects the consumptionstate by controlling the liquid sensor 802, and writes consumptionrelated data to the consumption data memory 804, and furthermore readsthe consumption related data out of the consumption data memory 804.

[0278] The recording device control unit 810 further comprises aconsumption data indicating unit 814 and a print operation control unit816. The consumption data indicating unit 814 indicates to a user theconsumption state data detected by the consumption detecting processunit 812 via a display 818 and a speaker 820. A diagram and the likewhich indicate an ink remaining amount are displayed in the display 818,and informative sound or composite sound indicating the ink remainingamount are output from the speaker 820. A proper operation may beadvised by the composite sound.

[0279] The print operation control unit 816 controls a print operationunit 822 based on the consumption state data detected by the consumptiondetecting process unit 812. The print operation unit 822 includes aprint head, a head moving device, a paper feeding device and so on. Forexample, the consumption detecting process unit 812 instructs the printoperation unit 822 to stop the printing operation when it is judged thatthe ink remaining amount is none.

[0280] The recording device control unit 810 may further control otherelements based on the detected consumption state. For example, there maybe provided an ink replenishing device and an ink cartridge replacementdevice and so on which are to be controlled by the recording devicecontrol unit 810.

[0281] Next, the consumption data memory 804 will be described indetail. The consumption data memory 804 stores the consumption relateddata which relate to the consumption state detected using the liquidsensor 802. The consumption related data include the detectedconsumption state data. The consumption state data are stored in aconsumption state data storing unit 806 of the consumption data memory804.

[0282] Moreover, detection of whether or not the liquid surface haspassed can be realized by the liquid sensor 802 on the basis of, forexample, the change in the above-described residual vibration state. Theresidual vibration state corresponds to the acoustic impedance. Whetheror not the liquid surface has passed may be detected by theabove-described reflected wave of the elastic wave.

[0283] Moreover, the consumption related data includes detectioncharacteristic data. The detection characteristic data are the data usedfor obtaining the consumption state by use of the liquid sensor. In thepresent embodiment, the detection characteristic data arecharacteristics to be detected according to the liquid consumptionstate. The detection characteristic data are the data, for example, onthe resonant frequency which represents a magnitude of the acousticimpedance. In this embodiment, detection characteristic data prior toconsumption and detection characteristic data after consumption arestored as the detection characteristic data. The detectioncharacteristic data prior to consumption indicates the detectioncharacteristic before the ink is consumed, that is, the detectioncharacteristic in an ink-full state. The detection characteristic dataafter consumption indicates the detection characteristic expected at thetime when the ink has been consumed up to a predetermined detectiontarget, and specifically indicates the detection characteristic when theink liquid level is below the liquid sensor 802.

[0284] The consumption detecting process unit 812 reads out thedetection characteristic data, and the ink consumption state is detectedbased on this detection characteristic data utilizing the liquid sensor802. When there is obtained a detection signal corresponding to thedetection characteristic prior to consumption, it seems that the inkconsumption has not progressed and the ink remaining amount is quite abit. At least, it can be known without fail that the ink liquid surfaceis above the liquid sensor 802. On the other hand, when there isobtained a detection signal corresponding to the detectioncharacteristic, the ink consumption has progressed and the ink remainingamount is low. The ink liquid surface is below the liquid sensor 802.

[0285] An advantageous aspect will be described in which the detectioncharacteristic data are stored in the consumption data memory 804. Thedetection characteristic is determined by a shape of the ink cartridge,the specifications of the liquid sensor and the specification of ink andother various factors. A change in a design such as a modificationthereto may change the detection characteristic. It is not easy to copewith the change of the detection characteristic when the consumptiondetecting process unit 812 always uses the same detection characteristicdata. On the other hand, in the present embodiment, the detectioncharacteristic data are stored in the consumption data memory 804 andutilized. Thus, it can easily cope with the change in the detectioncharacteristic. Even when an ink cartridge having new specifications isused, the printing apparatus can of course easily utilize the detectioncharacteristic data of that ink cartridge.

[0286] Further preferably, the detection characteristic data aremeasured for each ink cartridge and stored in the consumption datamemory 804. Though the specifications of the cartridges are the same,the detection characteristics differ due to manufacturing irregularity.For example, the detection characteristics differ depending on the shapeand thickness of the container. In the present embodiment, each inkcartridge has its own consumption data memory 804, so that its owndetection characteristic data can be stored in the consumption datamemory 804. Thus, the effect of the manufacturing irregularity on thedetection can be minimized, so as to improve detection accuracy. In thismanner, the present embodiment is advantageous in clarifying thedifference between the detection characteristics of the ink cartridges.

[0287] Moreover, the detection characteristic data may take a form of‘correction data’ serving as data for correcting the detection datawhich a printer driver of the printer (ink-jet recording apparatus) hasin advance. The printer driver has a reference characteristic for usewith detection. The detection characteristic data of the memory in thecartridge are data for correcting the reference characteristic data bycomplying with the type of the cartridge in use and the difference foundin the cartridge itself. The detection characteristic data may be aspecific correction value. Or, the detection characteristic data as thecorrection data may be an identification symbol. The correctioncorresponding to this identification symbol is performed in the printerside.

[0288] The consumption data memory 804 further stores the ink relateddata, as a memory means for the liquid container of the presentinvention. The consumption data memory 804 stores data on the type ofink. Moreover, this memory means stores a manufactured data, cleaningsequence data, image processing data and so on. These data can besuitably utilized in controlling the ink-jet recording apparatus.

[0289]FIG. 48 shows a processing of the consumption detecting processunit 812 utilizing the consumption data memory 804. First, whether ornot the ink cartridge is mounted is judged (S10). That a new or halfwayused ink cartridge is mounted can be detected. This processing uses aswitch (not shown) equipped with the ink-jet recording apparatus. Whenthe cartridge is mounted, detection characteristic data are read out ofthe consumption data memory 804 (S12) and then the consumption statedata are read out (S14). Consumption data indicating unit 814 and printoperation control unit 816 in the recording device control unit 810utilize the read-out consumption state data.

[0290] Using the liquid sensor 802, the consumption detecting processunit 812 detects the ink consumption state based on the read-outdetection characteristic data (S16). The detected consumption state isstored in the consumption data memory 804 (S18). This consumption stateis also utilized in the recording device control unit 810. Whether ornot the ink cartridge is removed is judged (S20). If not removed, returnto S16.

[0291] Next, a proper timing at which the detection characteristic dataare stored in the consumption data memory 804 will be described. Here,suppose that measured values of individual cartridges' detectioncharacteristics are stored.

[0292] Referring to FIG. 49, the consumption data memory 804 whichstores a standard detection characteristic is mounted on a new inkcartridge. After this ink cartridge is mounted to the ink-jet recordingdevice, the detection characteristic is measured. The detectioncharacteristic is measured between after the mounting and immediatelybefore the printing operation. In order to reliably carry out themeasurement, the detection characteristic is preferably measured afterthe mounting.

[0293] The detection characteristic is measured in a same manner asdetecting a normal ink consumption. The consumption state is detected byusing the liquid sensor 802, and its detected result (measured value) isrecorded as the detection characteristic of a new ink cartridge. Thestandard detection characteristic which was initially set is changed tothe measured value. The progression status of the ink consumption isdetermined from a difference between the detection characteristic and anewly obtained detection result.

[0294] According to the present embodiment, by adjusting the detectioncharacteristic at its initial stage, the irregularity caused by theindividual difference of the ink cartridges can be appropriatelyabsorbed, thus improving detection accuracy.

[0295] Another proper timing at which the detection characteristic dataare stored in the consumption data memory 804 will be described. Themeasured value of the detection characteristic data may be stored duringa manufacturing process of the ink cartridge. In this case too, theirregularity caused by the difference of individual cartridges can beproperly absorbed and can improve the detection accuracy. In this modeof embodiment, the detection characteristic prior to ink injection canbe measured and recorded. Thus, the measured values of both thedetection characteristics after and before the consumption can be storedin the consumption data memory 804.

[0296] Next, arrangement of the liquid sensor 802 and the consumptiondata memory 804 on the ink cartridge 800 will be described.

[0297] The liquid sensor 802 and the consumption data memory 804 maybearranged at different places on the ink cartridges 800 (see FIG. 1, FIG.7 and so on). The liquid sensor 802 and the consumption data memory 804may be arranged at different places on the same wall surface on the inkcartridge 800 (see FIGS. 42A, 42B and 42C). The liquid sensor 802 andthe consumption data memory 804 may be arranged respectively atdifferent wall surfaces of the ink cartridge 800 (see FIG. 1). The wallsurface on which the liquid sensor 802 is arranged may be positionedperpendicular to a wall surface on which the consumption data memory 804is arranged (see FIG. 7 and FIG. 9).

[0298] Referring to FIG. 50, the liquid sensor 802 and the consumptiondata memory 804 are provided preferably in a center portion of thecontainer in the cross direction. In FIG. 50, a supply port 830 isprovided on the lower surface of the cartridge. The liquid sensor 802and the consumption data memory 804 are provided in the vertical wall.These are all positioned in the container in the cross direction.Furthermore, the liquid sensor 802 and the consumption data memory 804are provided in the vicinity of the supply port 830. Advantageousaspects of this arrangement will be described below.

[0299]FIGS. 51A and 51B show an exemplary positioning of the supplyport. There is provided a quadrangle positioning projection 832 in theperiphery of the supply port (not shown) in the cartridge's lowersurface. The positioning projection 832 is inserted to and engaged witha positioning concave part 834 in the recording device side. Thepositioning concave part 834 has a form corresponding to the positioningprojection 832.

[0300] In the above structure, the ink cartridge is positioning-made tothe ink-jet recording apparatus at the supply port 830. The supply port830, the liquid sensor 802 and the consumption data memory 804 are allprovided in the central portion of the container in the cross direction.Even though the cartridge is mounted in such a manner of being rotated alittle bit in the horizontal direction about the supply port 830, anamount of the positioning displacement of the liquid sensor 802 and theconsumption data memory 804 caused by such the rotation is rather small,thereby the positioning accuracy can be improved.

[0301] As shown in the above examples, a high positioning accuracy isgenerally required for the supply port, so that a positioning structuresatisfying this requirement is provided. By providing the sensor andmemory in the vicinity of the supply port, the structure for use withsupply port positioning functions as the structure for use with thesensor and memory positioning. A single positioning structure operatesnot only as for the supply port but also as for the sensor and memory. Asimple structure makes possible the positioning of the sensor andmemory, and can also improve the detection accuracy.

[0302] In still another preferable embodiment, the liquid sensor 802 andthe consumption data memory 804 are provided on a same consumptiondetecting base plate. FIGS. 42A, 42B and 42C illustrate this structure.Referring to FIGS. 42A, 42B and 42C, the semiconductor memory 7 and theactuator 106 are provided on the same base plate 610. In this structure,the sensor and the memory can be mounted with ease. Moreover, in FIG.52, a consumption detecting base plate 836 is provided in the vicinityof the supply port 830 and is arranged in the center of the crossdirection of the container. Thereby, the positioning displacement can beminimized as described above.

[0303] Moreover, the mounting module in which the liquid sensor(actuator) and the mounting structure are integrally formed ispreferably mounted to the consumption detecting base plate. The mountingmodule is shown in FIG. 32 and so on. As described above, provision ofthe mounting module can protect the liquid sensor from external force,and can facilitate the mounting itself and simplify the operation, thusreducing the cost.

[0304] Referring back to FIGS. 42A, 42B and 42C, in the presentembodiment, there is provided a positioning structure whichpositioning-performs on the consumption detecting base plate against theliquid container. Though the reference numerals are omitted in FIG. 42B,a plurality of projections for use in mounting the base plate areprotruded outwardly from the ink cartridge as shown in a side view ofFIG. 42B. These projections function as positioning means. There areprovided five projections. As shown in the front view of FIG. 42C, thereare one projection in the upper portion, two in the central portion andanother two in the lower portion. These projections are inserted to andengaged with positioning holes (and mounting holes) of the base plate610. Since the base plate is accurately positioning-made by these, theaccuracy of mounting positions can be further improved.

[0305] The positioning structure of the base plate is not limited to theabove description. A cut-out groove may be engaged with the projection.The base plate may be inserted to and engaged with the concave part inthe container side. At the time of mounting, the periphery of the baseplate is constrained by the inner wall of the concave part, therebyrealizing the positioning. The circumference of the concave part may nothave the same shape as the circumference of the base plate. There areprovided at least two ribs in the concave part, and the base plate maybe sandwiched by these ribs.

[0306] Next, still another embodiment of the present invention will bedescribed. FIG. 53 is a functional block diagram for an ink-jetrecording apparatus equipped with the ink consumption detecting deviceaccording to the present embodiment. Differing from the structure inFIG. 47, an ink cartridge 900 consists only of a liquid sensor 902. Aconsumption data memory 910 is arranged in a recording device controlunit 904.

[0307] Similar to the structure in FIG. 47, the recording device controlunit 904 comprises a consumption detecting process unit 906, aconsumption data indicating unit 912 and a print operation control unit914. The consumption data indicating unit 912 indicates to the user thedetected consumption state by using a display 916 and a speaker 918. Theprint operation control unit 914 controls a print operation unit 920based on the detected consumption state.

[0308] The recording device control unit 904 further includes acartridge identifying unit 908. The ink consumption detecting devicecomprises the consumption detecting process unit 906, the cartridgeidentifying unit 908, the consumption data memory 910 and the liquidsensor 902.

[0309] The cartridge identifying unit 908 identifies an ink cartridgemounted in the ink-jet recording apparatus. Consumption related datacorresponding to the identified ink cartridge are read out of theconsumption data memory 910. As described above, the consumption relateddata include the consumption state data and the detection characteristicdata. The consumption state data obtained ass a result of detection areused in the consumption data indicating unit 912 and the print operationcontrol unit 914. The detection characteristic data are used for adetection process in the consumption detecting process unit 906.

[0310] Operations for the above described detection device will now bedescribed. When the ink cartridge 900 is mounted, the cartridgeidentifying unit 908 identifies the ink cartridge 900, so that theidentifying data are stored in the consumption data memory 910. Forexample, an identification number attached to the ink cartridge 900 isread out. The identifying data may be obtained from the liquid sensor902. As described using FIG. 49, at the time of mounting the cartridge,the detection characteristic is measured is stored in the consumptiondata memory 910. Utilizing this detection characteristic, theconsumption state is measured and is recorded in the consumption datamemory 910.

[0311] Suppose that the ink cartridge 900 is removed, and is now mountedagain. Then, the data on the cartridge mounted again remains in theconsumption data memory 910. That data are read out and used for aprocessing thereafter.

[0312] In this manner, according to the present embodiment, the similaradvantages to the above embodiments are obtained even if the consumptiondata memory is arranged in the recording device side.

[0313] Various modifications applying the present embodiment arepossible. For example, the consumption data memory may be providedseparately in the ink cartridge and the recording device control unit.One of the memory may record the consumption state while other memorymay record the detection characteristic data. Moreover, one may berecord the standard detection characteristic data while other may recordthe measured values of the detection characteristic.

[0314] In still another embodiment, the consumption data memory may beprovided in the ink cartridge while the liquid sensor may be provided inthe recording device side. Such structures may be found in FIGS. 15A and15B. Moreover, there may be provided a structure such that both theliquid sensor and the consumption data memory are provided in therecording apparatus.

[0315] Other modifications according to the present embodiment will bedescribed.

[0316] In the present embodiment, the consumption state obtained as aresult of the detection and the detection characteristic data for usewith detection are recorded in the consumption data memory as theconsumption related data. On the contrary, only one of the data may berecorded.

[0317] In FIG. 47 and FIG. 52, a single liquid sensor is provided in theink cartridge. In contrast, there may be provided a plurality of theliquid sensors. By utilizing these plural liquid sensors, detailedconsumption data can be recorded. Moreover, the detection characteristicdata are preferably recorded for each liquid sensor.

[0318] In the present embodiment, the liquid sensor is structured by thepiezoelectric element. As described before, the change in the acousticimpedance may be detected using the piezoelectric element. Theconsumption state may be detected utilizing the reflected wave of theelastic wave. The time required to travel from generation of the elasticwave to the arrival of the reflected wave is obtained. The consumptionstate may be detected by some principle utilizing a function of thepiezoelectric element.

[0319] In the present embodiment, the liquid sensor generates vibrationand also generates a detection signal which indicates the inkconsumption state. In contrast, the liquid sensor may be such that itdoes not generate vibration. That is, the liquid sensor may not be suchthat it does not generate both the vibration and the detection signaloutput. The vibration is generated by an actuator. Or, the liquid sensormay generate the detection signal which indicates the ink consumptionstate when vibration is caused in the ink cartridge accompanied by themovement of the carriage or the like. Then, without generating thevibration in a positive manner, the ink consumption is detected byutilizing the vibration caused naturally by the printing operation.

[0320] The function of the recording device control unit shown in FIG.47 and FIG. 52 may be realized by other than a computer of the recordingapparatus. Part of or whole function may be provided in an externallyprovided computer. The display and speaker may be provided in anexternally provided computer.

[0321] In the present embodiment, the liquid container is an inkcartridge while the liquid utilizing apparatus is an ink-jet recordingapparatus. However, the liquid container may be an ink container otherthan the ink cartridge and ink tank. For example, a sub-tank in the headside may serve as such. Moreover, the ink cartridge may be an cartridgeof the so-called off-carriage type. Moreover, the present invention maybe applied to a container which houses liquid other than ink.

[0322] As described above, by implementing the structure in which thememory means is provided in the liquid container, the detection resultcan be suitably utilized and the detection capability is significantlyimproved.

[0323] Although the present invention has been described by way ofexemplary embodiments, it should be understood that many changes andsubstitutions may be made by those skilled in the art without departingfrom the spirit and the scope of the present invention which is definedonly by the appended claims.

What is claimed is:
 1. A liquid container, comprising: a housingaccommodating liquid; a liquid supply opening formed in said housing; aliquid level detection device comprising a piezoelectric element; and astoring device mounted on a wall of said housing.
 2. The liquidcontainer according to claim 1, wherein said storing device storesinformation relating to a liquid consumption status.
 3. The liquidcontainer according to claim 2, wherein the information relating to theliquid consumption status is generated by said detecting device.
 4. Theliquid container according to claim 2, wherein the information comprisesa detection characteristics information employed for detecting theliquid consumption status by said detecting device.
 5. The liquidcontainer according to claim 2, wherein said storing device storesinformation indicating detection characteristics before the liquidcontained in the container starts to be consumed.
 6. The liquidcontainer according to claim 2, wherein said storing device storesinformation indicating detection characteristics which is expected to bedetected when the liquid is consumed up to be a predetermined targetlevel.
 7. The liquid container according to claim 4 to 6, wherein thedetection characteristics information comprises a resonance frequencycharacteristics.
 8. The liquid container according to claim 1, furthercomprising a substrate mounted on said housing, and said detectingdevice and said storing device are disposed on said substrate.
 9. Theliquid container according to claim 1, wherein said liquid leveldetection device detects a liquid consumption status on the basis of achange in the acoustic impedance.
 10. The liquid container according toclaim 1, wherein said detection device detects a liquid consumptionstatus on the basis of a change in a residual vibration thereof.
 11. Theliquid container according to claim 1, wherein said detection devicedetects a liquid consumption status on the basis of a change in aresonant frequency thereof.
 12. The liquid container according to claim1, wherein said storing device comprises a semiconductor memory.
 13. Anink cartridge for an ink jet printer, comprising: a housingaccommodating therein ink; an ink supply opening formed in said housing;an ink level detection device comprising a piezoelectric element; and astoring device mounted on a wall of said housing.
 14. The ink cartridgeaccording to claim 13, wherein said storing device stores informationrelating to an ink consumption status.
 15. The ink cartridge accordingto claim 14, wherein the information relating to the ink consumptionstatus is generated by said detecting device.
 16. The ink cartridgeaccording to claim 14, wherein the information comprises a detectioncharacteristics information employed for detecting the ink consumptionstatus by said detecting device.
 17. The ink cartridge according toclaim 16, wherein said storing device stores information indicatingdetection characteristics before the ink contained in said housingstarts to be consumed.
 18. The ink cartridge according to claim 16,wherein said storing device stores information indicating detectioncharacteristics which is expected to be detected when ink is consumed upto be a predetermined target level.
 19. The ink cartridge according toclaim 16 to 18, wherein the detection characteristics informationcomprises a resonance frequency characteristics.
 20. The ink cartridgeaccording to claim 13, further comprising a substrate mounted on saidhousing, and said detecting device and said storing device are disposedon said substrate.
 21. The ink cartridge according to claim 13 whereinsaid ink level detection device detects an ink consumption status on thebasis of a change in the acoustic impedance.
 22. The ink cartridgeaccording to claim 13, wherein said detection device detects a liquidconsumption status on the basis of a change in a residual vibrationthereof.
 23. The ink cartridge according to claim 13, wherein saiddetection device detects a liquid consumption status on the basis of achange in a resonant frequency thereof.
 24. The ink cartridge accordingto claim 18, wherein said storing device comprises a semiconductormemory.
 25. An ink jet printer, comprising: a print operation sectioncomprising a print head ejecting ink droplets through nozzles; an inkcartridge connecting with said print head for accommodating ink therein,said ink cartridge comprising: a housing accommodating therein ink; anink supply opening formed in said housing; an ink level detection devicecomprising a piezoelectric element; and a storing device mounted on awall of said housing, a control section connecting with said ink leveldetection device and said storing device of said ink cartridge.
 26. Theink jet printer according to claim 25 wherein said ink level detectiondevice of said ink cartridge detects an ink consumption status on thebasis of a change in the acoustic impedance.
 27. The ink jet printeraccording to claim 25, wherein said detection device detects an inkconsumption status on the basis of a change in a residual vibrationthereof.
 28. The ink jet printer according to claim 25, wherein saiddetection device detects an ink consumption status on the basis of achange in a resonant frequency thereof.
 29. The ink jet printeraccording to claim 25, wherein said storing device stores informationrelating to an ink consumption status.
 30. The ink jet printer accordingto claim 25, wherein said control section comprises: a signal processingsection connecting with said detection device for receiving an outputsignal thereof; and a head control section connecting with said printoperation section, said print control section controlling said printoperation section in accordance with a signal processed by said signalprocessing section.
 31. A liquid detecting device, comprising: asubstrate; a sensor mounted on a first portion of said substrate, saidsensor comprising a piezoelectric element; and a memory mounted on asecond portion of said substrate.
 32. The liquid detecting substrateaccording to claim 31, wherein said sensor detects a liquid consumptionstatus on the basis of a change in a residual vibration thereof.
 33. Theliquid detecting substrate according to claim 31, wherein said sensordetects a liquid consumption status on the basis of a change in aresonant frequency thereof.
 34. A liquid detection system, comprising: aliquid container comprising: a housing accommodating therein liquid; aliquid supply opening formed in said housing; and a liquid leveldetection device mounted on said housing, said detection devicecomprising a piezoelectric element, a storing device mounted on a wallof said housing of said liquid container; and a control sectionconnecting with said ink level detection device and said storing device.35. The liquid detection system according to claim 34, wherein saidliquid level detection device of said liquid container detects an inkconsumption status on the basis of a change in the acoustic impedance.36. The liquid detection system according to claim 34, wherein saiddetection device detects a liquid consumption status on the basis of achange in a residual vibration thereof.
 37. The liquid detection systemaccording to claim 34, wherein said detection device detects a liquidconsumption status on the basis of a change in a resonant frequencythereof.
 38. The liquid detection system according to claim 34, whereinsaid storing device stores information relating to a liquid consumptionstatus.
 39. The liquid detection system according to claim 34, whereinsaid control section comprises: a signal processing section connectingwith said detection device for receiving an output signal thereof; andan operating section connecting to said signal processing section, saidoperating section activating a predetermined operation of an externalsystem in accordance with an output signal of said control section. 40.The liquid detection system according to claim 39, further comprising aninformation indicating section, and said control section furthercomprises an information control section receiving an output signal ofsaid signal processing section and activating said informationindicating section.
 41. A method of detecting a liquid consumptionstatus of liquid contained in a liquid container, comprising steps of:reading out information relating to a detection characteristics; readingout information relating to a liquid consumption status; detecting a newliquid consumption status of liquid contained in the liquid container;and storing the newly detected liquid consumption status in a memorymounted on the liquid container.
 42. The liquid consumption statusdetecting method according to claim 41, further comprising a step ofstoring the detection characteristics in the memory mounted on theliquid container.
 43. The liquid consumption status detecting methodaccording to claim 41, further comprising a step of judging whether theliquid container is installed at a predetermined position.
 44. Theliquid consumption status detecting method according to claim 41,further comprising a step of judging whether the liquid container isdetached from a predetermined position.
 45. The liquid consumptionstatus detecting method according to claim 41, further comprising a stepof storing information relating to liquid type in the memory mounted onthe liquid container.
 46. The liquid consumption status detecting methodaccording to claim 41, further comprising a step of activating anexternal system in accordance with the detection result of saiddetection step.
 47. The liquid consumption status detecting methodaccording to claim 41, wherein said detection step comprising a step ofdetecting a change in the acoustic impedance.
 48. The liquid consumptionstatus detecting method according to claim 41, wherein said detectionstep comprising a step of detecting a change in a residual vibration.49. The liquid consumption status detecting method according to claim41, wherein said detection step comprising a step of detecting a changein a resonant frequency.
 50. The liquid consumption status detectingmethod according to claim 41, further comprising a step of processing asignal resulting from said detection step and a step of activating anexternal system in accordance with the result of said processing step.